Chapter One.

The Devil’s Dice.

“Do get rid of the girl! Can’t you see that she’s highly dangerous!” whispered the tall, rather overdressed man as he glanced furtively across the small square shop set with little tables, dingy in the haze of tobacco-smoke. It was an obscure, old-fashioned little restaurant in one of London’s numerous byways—a resort of Germans, naturalised and otherwise, “the enemy in our midst,” as the papers called them.

“I will. I quite agree. My girl may know just a little too much—if we are not very careful.”

“Ah! she knows far too much already, Drost, thanks to your ridiculous indiscretions,” growled the dark-eyed man beneath his breath. “They will land you before a military court-martial—if you are not careful!”

“Well, I hardly think so. I’m always most careful—most silent and discreet,” and he grinned evilly.

“True, you are a good Prussian—that I know; but remember that Ella has, unfortunately for us, very many friends, and she may talk—women’s talk, you know. We—you and I—are treading very thin ice. She is, I consider, far too friendly with that young fellow Kennedy. It’s dangerous—distinctly dangerous to us—and I really wonder that you allow it—you, a patriotic Prussian!”

And, drawing heavily at his strong cigar, he paused and examined its white ash.

“Allow it?” echoed the elder man. “How, in the name of Fate, can I prevent it? Suggest some means to end their acquaintanceship, and I am only too ready to hear it.”

The man who spoke, the grey-haired Dutch pastor, father of Ella Drost, the smartly-dressed girl who was seated chatting and laughing merrily with two rather ill-dressed men in the farther corner of the little smoke-dried place, grunted deeply. To the world of London he posed as a Dutchman. He was a man with a curiously triangular face, a big square forehead, with tight-drawn skin and scanty hair, and broad heavy features which tapered down to a narrow chin that ended in a pointed, grey, and rather scraggy beard.

Theodore Drost was about fifty-five, a keen, active man whose countenance, upon critical examination, would have been found to be curiously refined, intelligent, and well preserved. Yet he was shabbily dressed, his long black clerical coat shiny with wear, in contrast with the way in which his daughter—in her fine furs and clothes of the latest mode—was attired. But the father, in all grades of life, is usually shabby, while his daughter—whatever be her profession—looks smart, be it the smartness of Walworth or that of Worth.

As his friend, Ernst Ortmann, had whispered those warning words he had glanced across at her, and noting how gaily she was laughing with her two male friends, a cigarette between her pretty lips, he frowned.

Then he looked over to the man who had thus urged discretion.

The pair were seated at a table, upon which was a red-bordered cloth, whereon stood two half-emptied “bocks” of that light beer so dear to the Teuton palate. They called it “Danish beer,” not to offend English customers.

The girl whose smiles they were watching was distinctly pretty. She was about twenty-two, with a sweet, eminently English-looking face, fair and quite in contrast with the decidedly foreign, beetle-browed features of the two leering loafers with whom she sat laughing.

Theodore Drost, to do him justice, was devoted to his daughter, who, because of her childish aptitude, had become a dancer on the lowest level of the variety stage, a touring company which visited fifth-rate towns. Yet, owing to her discovered talent, she had at last graduated through the hard school of the Lancashire “halls,” to what is known as the “syndicate halls” of London.

From a demure child-dancer at an obscure music-hall in the outer suburbs, she had become a noted revue artiste, a splendid dancer, who commanded the services of her own press-agent, who in turn commanded half-a-dozen lines in most of the London morning papers, both her prestige and increased salary following in consequence. The British public so little suspect the insidious influence of the press-agent in the formation of modern genius. The press-agent has, in the past, made many a mediocre fool into a Birthday Baronet, or a “paid-for Knight,” and more than one has been employed in the service of a Cabinet Minister. Oh what sheep we are, and how easily we are led astray!

On that wintry night, Ella Drost—known to the theatre-going public as Stella Steele, the great revue artiste whose picture postcards were everywhere—sat in that stuffy, dingy little restaurant in Soho, sipping a glass of its pseudo-Danish lager, and laughing with the two unpresentable men before her.

Outside the unpretentious little place was written up the single word “Restaurant.” Its proprietor a big, full-blooded, fair-bearded son of the Fatherland, had kept it for twenty years, and it had been the evening rendezvous of working-class Germans—waiters, bakers, clerks, coiffeurs, jewellers, and such-like.

Here one could still revel in Teuton delicacies, beer brewed in Hamburg, but declared to be “Danish,” the succulent German liver sausage, the sausage of Frankfort—boiled in pairs of course—the palatable sauerkraut with the black sour bread of the Fatherland to match.

“I wish you could get rid of Kennedy,” said Ortmann, as he again, in confidence, bent across the table towards Ella’s father. “I believe she’s in collusion with him.”

“No,” laughed the elder man, “I can’t believe that. Ella is too good a daughter of the Fatherland.” He was one of Germany’s chief agents in England, and had much money in secret at his command.

Ortmann screwed up his eyes and pursed his lips. He was a shrewd, clever man, and very difficult to deceive.

“Money is at stake, my dear Drost,” he whispered very slowly—“big money. But there is love also. And I believe—nay, I’m sure—that Kennedy loves her.”

“Bah! utterly ridiculous!” cried her father. “I don’t believe that for a single moment. She’s only fooling him, as she has fooled all the others.”

“All right. But I’ve watched. You have not,” was the cold reply.

From time to time the attractive Ella, on her part, glanced across at her father, who was whispering with his overdressed companion, and, to the keen observer, it would have been apparent that she was only smoking and gossiping with that pair of low-bred foreigners for distinct purposes of her own.

The truth was that, with her woman’s instinct, feminine cleverness and ingenuity, she, being filled with the enthusiasm of affection for her aviator-lover, was playing a fiercely desperate part as a staunch and patriotic daughter of Great Britain.

The hour was late. She had hurried from the theatre in a taxi, the carmine still about her pretty lips, her eyes still darkened beneath, and the greasepaint only roughly rubbed off. The great gold and white theatre near Leicester Square, where, clad in transparencies, she was “leading lady” in that most popular revue “Half a Moment!” had been packed to suffocation, as indeed it was nightly. Officers and men home on leave from the battle-front all made a point of seeing the pretty, sweet-faced Stella Steele, who danced with such artistic movement, and who sang those catchy patriotic songs of hers, the stirring choruses of which even reached the ears of the Bosches in their trenches. And in many a British dug-out in Flanders there was hung a programme of the revue, or a picture postcard of the seductive Stella.

There were, perhaps, other Stella Steeles on the stage, for the name was, after all, not an uncommon one, but this star of the whole Steele family had arisen from the theatrical firmament since the war. She, the laughing girl who, that night, sat in that obscure, smoke-laden little den of aliens in Soho, was earning annually more than the “pooled” salary of a British Cabinet Minister.

That Stella was a born artiste all agreed—even her agent, that fat cigar-smoking Hebrew cynic who regarded all stage women as mere cattle out of whom he extracted commissions. To-day nobody can earn unusual emoluments in any profession without real merit assisted by a capable agent.

Stella Steele was believed by all to be thoroughly British. Nobody had ever suspected that her real name was Drost, nor that her bespectacled and pious father had been born in Stuttgart, and had afterwards become naturalised as a Dutchman before coming to England. The cigarette-smoking male portion of the khaki-clad crowd who so loudly applauded her every night had no idea that their idol had been born in Berlin. Isaac Temple, the mild-mannered press-agent whom she employed, had always presented her, both to press and public, and sent those artistic photographs of hers to the Sunday illustrated papers, as daughter of a London barrister who had died suddenly, leaving her penniless. Thus had the suspicious connection with Drost been always carefully suppressed, and Ella lived very quietly in her pretty flat in Stamfordham Mansions, situate just off the High Street in Kensington.

Her father—her English mother, whom she had adored, being long ago dead—lived a quiet, secluded life in one of those rather large houses which may be found on the south side of the Thames between Putney and Richmond. Pastor Drost had, it was believed by the Dutch colony in London, been a missionary for some years in Sumatra, and, on more than one occasion, he had lectured upon the native life of that island. Therefore he had many friends among Dutch merchants and others, who all regarded him as a perfectly honest and even pious, if rather eccentric, man.

At times he wore big round horn-rimmed glasses which grossly magnified his eyes, giving him a strange goggled appearance. The world, however, never knew that Pastor Drost’s only daughter was that versatile dancer who, dressed in next-to-nothing, nightly charmed those huge enthusiastic audiences in the popular revue, “Half a Moment!”

Until three months after the outbreak of war Ella had regarded her father’s idiosyncrasies with some amusement, dismissing them as the outcome of a mind absorbed in chemical experiment, for though none save herself was aware of it, the long attic beneath the roof of her father’s house—the door of which Theodore Drost always kept securely locked—was fitted as a great chemical laboratory, where he, as a professor of chemistry, was constantly experimenting.

After the outbreak of war, by reason of a conversation she one day overheard between her father and his mysterious visitor, Ernst Ortmann, her suspicions had become aroused. Strange suspicions they indeed were. But in order to obtain confirmation of them, she had become more attached to her father, and had visited him far more frequently than before, busying herself in his domestic affairs, and sometimes assisting the old widow, Mrs Pennington, who acted as his single servant.

Two years prior to the war, happening upon that house, which was to be sold cheap, Ella had purchased it, ready furnished as it was, and given it as a present to her father as a place in which he might spend his old age in comfort. But until that night when she had overheard the curious conversation—which she had afterwards disclosed in confidence to her lover, Lieutenant Seymour Kennedy, Flight-Commander of the Naval Air Service—she had never dreamed that her father, the good and pious Dutchman who had once been a missionary, was an enemy alien, whose plans were maturing in order to assist a great and desperate conspiracy organised by the secret service of the German Fatherland.

On a certain well-remembered November evening she had revealed to Kennedy the truth, and they had both made a firm compact with each other. The plotter was her father, it was true. But she was a daughter of Great Britain, and it was for her to combat any wily and evil plot which might be formed against the land which had given birth to her adored mother.

She loved Seymour Kennedy. A hundred men had smiled upon her, bent over her little hand, written to her, sent her flowers and presents, and declared to her their undying affection. It is ever so. The popular actress always attracts both fools and fortunes. But Ella, level-headed girl as she was, loved only Seymour, and had accepted the real, whole-hearted and honest kisses which he had imprinted upon her lips. Seymour Kennedy was a gentleman before being an officer, which could not, alas! be said of all the men in the services in war-time.

Ella Drost was no fool, her dead mother had always instilled into her mind that, though born of a German father, yet she was British, an argument which, if discussed legally, would have been upset, because, having, unfortunately, been born in Berlin, she was certainly a subject of the German octopus. At the time of her birth her father had occupied a very important position among professors—half the men in the Fatherland were professors of something or other—yet Drost had been professor of chemistry at the Imperial Arsenal at Spandau—that great impregnable fortress in which the French war indemnity of 1870 had been locked up as the war-chest of golden French louis.

How strange it was! And yet it was not altogether strange. Ella, whose heart—the heart of a true British girl trained at her mother’s knee—had discovered a curious “something” and, aided by her British airman lover, was determined to carry on her observations, at all hazards, to the point of ascertaining the real truth.

England was at war at the battle-front—and she, a mere girl, was at war with the enemy in its midst.

Three-quarters of an hour later Ella—whose comfortable car was waiting outside the dingy little place—had driven her father home, but on the way she expressed her decision to stay with him, as it was late and her French maid, Mariette, had no doubt gone to bed.

As they stood in her father’s large, well-furnished dining-room, Ella drew some lemonade from a siphon and then, declaring that she was sleepy, said she would retire.

“All right, my dear,” replied the old man. “All right. You’ll find your room quite ready for you. I always order that it shall be kept ready for you. Let’s see! You were here a week ago—so the bed will not be damp.”

The girl bent and imprinted a dutiful kiss upon her father’s white brow, but, next instant, set her teeth, and in her blue eyes—though he did not see it—there showed a distinct light of suspicion.

Then she switched on the light on the stairs, loosened her furs, and ascended to the well-furnished room that was always regarded as hers.

The room in which Ella found herself was large, with a fine double wardrobe, a long cheval-glass, and a handsome mahogany dressing-table. The curtains and upholstery were in pale-blue damask, while the thick plush carpet was of a darker shade.

Instead of retiring, Ella at once lit the gas-stove, glanced at her wristlet-watch, the face of which was set round with diamonds, and then flung herself into a deep armchair to think, dozing off at last, tired out by the exertion of her dancing.

The striking of the little gilt clock upon the mantelshelf presently aroused her, and, rising, she switched off the light and, creeping upon tiptoe, slowly opened her bedroom door and listened attentively.

Somewhere she could hear the sound of men’s voices. One she recognised as her father’s.

“That’s Nystrom again! That infernal hell-fiend!” she whispered breathlessly to herself.

Then, removing her smart shoes and her jingling bangles, she crept stealthily forth along the soft carpet of the corridor, and with great care ascended the stairs to the floor above, which was occupied by that long room, the door of which was always kept locked—the room in which her father conducted his constant experiments.

From the ray of light she saw that the door was ajar. Within, the two men were talking in low deep tones in German.

She could hear a hard sound, as of metal being filed down, and more than once distinguished the clinking of glass, as though her father was engaged in some experiment with his test-tubes and other scientific paraphernalia which she had seen arranged so methodically upon the two long deal tables.

“What has Ortmann told you?” asked Theodore Drost’s midnight visitor, while his daughter stood back within the long cupboard on the landing, listening.

“He says that all is in order. We have a friend awaiting us.”

“And the payment—eh?” asked the man Nystrom, a German who had been naturalised as a Swede, and now lived in London as a neutral. As a professor of chemistry he had been well-known in Stockholm and, being a bosom friend of the Dutch pastor’s, the pair often delighted in dabbling together in their favourite science.

“I shall meet Ernst on Friday night. If we are successful, he will pay two thousand pounds—to be equally divided between us.”

“Good,” grunted the other. “We shall be successful, never fear—that is if Ortmann has arranged things at his end. Himmel ! what a shock it will be—eh, my friend?—worse than the Zeppelins!”

Theodore Drost laughed gleefully, while his daughter, daring to creep forward again, peered through the crack of the door and saw the pair bending over what looked like a square steel despatch-box standing upon the table amid all the scientific apparatus.

The box, about eighteen inches long, a foot wide, and six inches deep, was khaki-covered, and, though she was not aware of it at the time, it was of the exact type used in the Government offices.

Fridtjof Nystrom, a tall, dark-haired man, with a red, blotchy face, rather narrow-eyed and round-shouldered, was adjusting something within the box, while old Drost, who had discarded his shabby black pastor’s coat and now wore a dark-brown jacket, took up a small glass retort beneath which the blue flame of a spirit-lamp had been burning, and from it he poured a few drops of some bright red liquid into a tiny tube of very thin glass. Then, taking a small blow-pipe, he blew the flame upon the tube until he had melted the glass and sealed it hermetically.

The blotchy-faced man watched this latter operation with great interest, saying:

“Have a care now, my dear Theodore. The least mishap, and not a piece of either of us would remain to tell the story.”

“ Ja ! Leave that to me,” answered Ella’s father. “We do not, I agree, desire a repetition of the disaster which happened last week.”

Ella, hearing those words, stood aghast.

A week before all London had been mystified and horrified by a most remarkable explosion which had occurred one night in a house in one of the outer suburbs, whereby the place had been set on fire and utterly demolished. Whoever were present in the house had been blown to atoms, for no trace of the occupants, or of what had caused the disaster, had been discovered. At first it was believed to have been caused by an incendiary bomb dropped from the air, but expert evidence quickly established the fact that something within the house had exploded.

Was it possible that her father and his dastardly companions possessed knowledge of what had actually occurred there?

Suddenly, Drost having handed the tiny sealed tube to Nystrom, the latter proceeded to place it in position within the box, using most infinite care. Then her father turned upon his heel, and came forward to the door behind which his daughter was standing.

In a second Ella had shrunk back noiselessly into the cupboard, which the old man passed in the darkness, and descended the stairs.

He had passed the door of Ella’s room when, having gained the bottom of the stairs, he paused and whistled softly. In a few seconds Nystrom came forth.

“Come, Fridtjof,” he urged in a low whisper. “Let us drink to the success of our expedition to-night, and the victory of our dear Fatherland,” an invitation which his visitor at once accepted.

Ella heard the two men descend, making but little noise, and a moment later she crept into the long, well-lit laboratory where, upon the table, stood the big official-looking despatch-box.

A second’s glance was sufficient to reveal the truth even to her, a woman unversed as she was in such things. It was a most ingeniously-constructed infernal machine which would detonate the quantity of high-explosive which she saw had been placed within.

Though her father had taken the greatest precaution to conceal from his daughter the exact line of his chemical experiments, yet, if the truth be told, Ella and her lover had watched carefully, and Kennedy—who had shared his well-beloved’s suspicions—had ascertained, without doubt, that Drost and Nystrom had been engaged in that long, low room beneath the roof, in treating toluene with nitric and sulphuric acid for several days under heat thus producing tri-nitro-toluene—or trotul—that modern high-explosive, of terrible force, which was rapidly superseding picric acid as a base for shell-fillers.

At a glance Ella saw that the square steel bomb, fashioned like an official despatch-box, was filled with this highly dangerous explosive, and that the thin glass tube which, when broken, would explode it, had already been placed in position. Such a bomb, on exploding in a confined space, must work the most terrible havoc.

In those few seconds the girl verified the suspicion which Kennedy had entertained. Some desperate outrage was to be committed. That was quite certain.

A bomb from a Zeppelin could not cause greater injury to life and property than that ingeniously contrived machine, the delicately constructed fuse of which, fashioned on the lathe by her father’s own hands, could be arranged to detonate at any given time.

A second’s pause, and then the girl, beneath her breath, took a deep oath of vengeance against the ruler of that hated land wherein she had been born.

“Thank Heaven that I am English!” she whispered to herself. “And I will live—and die, if necessary—as an English girl should.”

With those words upon her lips she crept away from the laboratory, down the stairs to her room, and, swiftly putting on her fur coat, she went into the basement, from which she let herself out noiselessly, and then hurried through the night, in the direction of Hammersmith Bridge.

On gaining the bridge, she saw the red rear-light of a motor-car, and knew that it was Kennedy’s. He had drawn up against the kerb, and had been consuming cigarettes waiting in impatience for a long time.

“Well, darling?” he asked, as they met. “I got your message from the theatre to-night. What is in progress?”

“Something desperate,” was her quick reply. “Let’s get into the car and I’ll explain.”

Both entered the comfortable little coupé, and then Ella explained in detail to her flying-man lover all that she had discovered.

The keen-faced, clean-shaven young officer in uniform who, before he had gone in for aviation duties, had graduated at Osborne, and afterwards been at sea and risen from “snotty” to lieutenant, sat beside her, listening intently.

“Just as we thought, darling,” he remarked. “For me, loving you so dearly, it is a terrible thing to know that your father is such a deadly and ingenious enemy of ours as he is. Truly the German plotters are in our midst in every walk of life, from high society down to the scum of the East End. The brutes are out to win the war by any underhand, subtle, and brutal means in their power. But we have discovered one line of their enemy intentions and, with your aid, dearest, we will follow it up and, without exposing your father and bringing disgrace upon you, we’ll set out to combat them every time.”

“Agreed, dear,” declared the girl with patriotic enthusiasm. “I have told you all along of my suspicions. To-night they are verified. Father, and that devilish scoundrel, Nystrom, mean mischief—for payment too—one thousand pounds each!”

“The infernal brutes!” exclaimed the man at her side. “At least it is to you, dear, that this discovery is due. I had no idea what you were after when you sent me that wire to-night.”

“I suspected, and my suspicions have proved correct,” said the girl. “Shall we wait here and follow them? They must cross the river if they intend to go into London to-night—as no doubt they do.”

“Yes. They believe you to be soundly asleep, I suppose?”

“I locked my door, and have the key in my pocket,” replied his well-beloved with a light laugh.

And she, putting her ready lips to his, sat with him in the car at the foot of the long suspension-bridge, waiting for any person to cross.

They remained there for perhaps half-an-hour, ever eager and watchful. Several taxis passed, but otherwise all was quiet in the night. Now and then across the sky fell the big beams of searchlights seeking enemy aircraft, and these they were watching, when, suddenly, a powerful, dark-painted car approached.

“Look!” cried Ella. “Why, that’s that fellow Benyon’s car—he’s a friend of Dad’s!”

Next moment it flashed past, and beneath the dim light at the head of the bridge they both caught a glimpse of two men within, one of whom was undoubtedly Theodore Drost.

“Quick!” cried Ella. “Let’s follow them! Fortunately you have to-night another car, unknown to them!”

In an instant Seymour Kennedy had started his engine, and slowly he drew out across the bridge, speeding after the retreating car over the river, along Bridge Road to Hammersmith Broadway and through Brook Green, in a direction due north.

Through the London streets it was not difficult at that hour to follow the red tail-light of the car in which Drost sat with his bosom friend George Benyon, a mysterious person who seemed to be an adventurer, and who lived somewhere in York or its vicinity.

“I wonder if they are going up to York?” Ella asked, as she sat in the deep seat of the coupé at her lover’s side.

“We’ll see. If they get on to the North Road we shall at once know their intentions,” was her lover’s reply.

Half-an-hour later the pseudo-Dutch pastor and his companion, driven by rather a reckless young fellow, were on the main Great North Road, and Kennedy, possessing a lighter and superior car, had no misgivings as to overtaking them whenever he wished.

On through the night they went, passing Barnet, Hatfield, Hitchin, the cross-roads at Wansford, and up the crooked pebbled streets of Stamford, until in the grey of morning they descended into Grantham, with its tall spire and quaint old Angel and Crown Hotel.

It was there that Drost and his companion breakfasted, while Ella and her lover waited and watched.

Some devilish plot of a high-explosive nature was in progress, but of its true import they were in utter ignorance. Yet their two British hearts beat quickly in unison, and both were determined to frustrate the outrage, even at the sacrifice of their own lives.

At three o’clock in the afternoon Drost and Benyon drew up at the Station Hotel at York, and there took lunch, while Ella and her lover ate a very hurried and much-needed meal in the railway-buffet in the big station adjoining.

Then, after they had watched the departure of the big mud-spattered car which contained the two conspirators, they were very quickly upon the road again after them.

Out of the quiet old streets of York city, past the Minster, they turned eastward upon that well-kept highway which led towards the North Sea Coast.

An hour’s run brought them to the pleasant town which I must not, with the alarming provisions of the Defence of the Realm Act before me, indicate with any other initial save that of J—.

The town of J—, built upon a deep and pretty bay forming a natural harbour with its breakwater and pier, was, in the pre-war days, a popular resort of the summer girl with her transparent blouses and her pretty bathing costumes, but since hostilities, it was a place believed to be within the danger zone.

As they descended, by the long, winding road, into the town, they could see, in the bay, a big grey four-funnelled first-class cruiser lying at anchor, the grey smoke curling lazily from her striped funnels—resting there no doubt after many weeks of patrol duty in the vicinity of the Kiel Canal.

Indeed, as they went along the High Street, they saw a number of clear-eyed liberty men—bluejackets—bearing upon their caps the name H.M.S. Oakham .

The car containing Ella’s father and his companion pulled up at the Palace Hotel, a big imposing place, high on the cliff, therefore Kennedy, much satisfied that he had thus been able to follow the car for over two hundred miles, went on some little distance to the next available hotel.

This latter place, like the Palace, afforded a fine view of the bay, and as they stood at a window of the palm-lined lounge, they could see that upon the cruiser lights were already appearing.

Kennedy called the waiter for a drink, and carelessly asked what was in progress.

“The ship—the Oakham —came in the day before yesterday, sir,” the man replied. “There’s a party on board this evening, they say—our Mayor and corporation, and all the rest.”

Ella exchanged glances with her lover. She recollected that khaki-covered despatch-box. Had her father brought with him that terrible death-dealing machine which he and Nystrom had constructed with such accursed ingenuity?

The hotel was deserted, as east coast hotels within the danger zone usually were in those war days, remaining open only for the occasional traveller and for the continuity of its licence. The great revue star had sent a telegram to her manager, asking that her understudy should play that night, and the devoted pair now stood side by side watching how, in the rapidly falling night, the twinkling electric lights on board the fine British cruiser became more clearly marked against the grey background of stormy sea and sky.

“I wonder what their game can really be?” remarked the young flying-officer reflectively as, alone with Ella, his strong arm crept slowly around her neat waist.

From where they stood they were afforded a wide view of the broad road which led from the town down to the landing-stage, from which the cruiser’s steam pinnace and picket-boat were speeding to and fro between ship and shore. A dozen or so smart motor-cars had descended the road, conveying the guests of the captain and officers who, after their long and unrelaxing vigil in the North Sea, certainly deserved a little recreation. Then, as the twilight deepened and the stars began to shine out over the bay, it was seen that the procession of guests had at last ended.

“I think, Ella, that we might, perhaps, go down to the landing-stage,” said Kennedy at last—“if you are not too tired, dear.”

“Tired? Why, of course not,” she laughed, and after he had helped her on with her coat, they both went out, passing down to the harbour by another road.

For fully an hour they idled about in the darkness, watching the swift brass-funnelled pinnace which, so spick and span, and commanded by a smart lad fresh from Osborne, was making the journey regularly between ship and quay. Away in the darkness the lights on the cruiser’s quarter-deck reflected into the sea, while ever and anon the high-up masthead signal-lamp winked in Morse code to the coastguard station five miles distant across the bay.

While they were watching, the pinnace came in again, whereupon the smart figure of a naval officer in his topcoat appeared within the zone of light, and descended the steps, shouting in an interrogative tone:

“ Oakham ?”

“Ay, ay, sir!” came a cheery voice from the pinnace.

“Look!” gasped Ella, clinging to her lover’s arm. “Why—it’s Benyon—dressed as a naval lieutenant! He’s going on board, and he’s carrying that despatch-box with him!”

Indeed, he had handed the heavy box to one of the men, and was at that moment stepping into the pinnace.

“Off to the ship—as quick as you can!” they heard him order, while, next moment, the boat was cast loose and the propeller began to revolve.

“We haven’t a second to lose!” whispered Kennedy who, as soon as the pinnace was around the pier-head, called out “Boat!” In an instant half-a-dozen men, noticing that he was a naval officer, were eagerly crowding around him.

“I want to follow that pinnace—quick!” he said. “Three men—and you can sail out there. The wind’s just right.”

In a few moments a boat came alongside the steps, and into it the pair stepped, with three hardy North Sea boatmen.

Quickly sail was set and, favoured by a fresh breeze, the boat slowly heeled over and began to skim across the dark waters.

Already the light on the pinnace showed far away, it having nearly reached the ship. Therefore Kennedy, in his eagerness, stirred the three men to greater effort, so that by rowing and sailing by turns, they gradually grew nearer the long, dark war-vessel, while Ella sat clasping her well-beloved’s hand in the darkness, and whispering excitedly with him.

Those were, indeed, moments of greatest tension, away upon that dark wintry sea beyond the harbour, that wide bay which, on account of its unusual depth and exposed position, was never considered a very safe anchorage.

Their progress seemed at a snail’s pace, as it always seems upon the sea at night. They watched the pinnace draw up, and they knew that the man, Benyon, who, though German-born, had lived in London the greater part of his life—was on board carrying that terrible instrument of death that had been cleverly prepared in such official guise.

At last—after an age it seemed—the boat swung in beside the lighted gangway against the pinnace, and Kennedy, stepping nimbly up, said to the sentry on board:

“Let nobody pass up or down, except this lady.” Then, seeing the officer on duty, he asked if a lieutenant had arrived on board with a despatch-box.

“Yes. I’ve sent him down to the captain,” was the reply.

“Take me to the captain at once, please,” Kennedy said in a calm voice. “There’s no time to lose. There’s treachery on board!”

In a second the officer was on the alert and ran down the stern gangway which led direct to the captain’s comfortable cabin, with its easy-chairs covered with bright chintzes like the small drawing-room of a country house.

Kennedy followed with Ella, but the captain was not there. The sentry said he was in the ward-room, therefore the pair waited till he came forward eagerly.

“Well,” asked the grey-haired captain with some surprise, seeing an officer and a lady. “What is it?”

“Have you received any despatches to-night, sir?” Kennedy inquired.

“No. What despatches?” asked the captain.

Then, in a few brief words, Kennedy explained how he had watched a man in naval uniform come off in the pinnace, carrying a heavy despatch-box. The man had passed the sentry and been directed below by the officer on duty. But he had never arrived at the captain’s cabin.

The “owner,” as the captain of a cruiser is often called by his brother officers, was instantly on the alert. The alarm was given, and the ship was at once thoroughly searched, especially the ammunition stores, where, in the flat close to the torpedoes on the port side, the deadly box was discovered. The guests knew nothing of this activity on the lower deck, but the two men who found the box heard a curious ticking within, and without a second’s delay brought it up and heaved it overboard.

Then again the boatswain piped, and every man, as he stood at his post, was informed that a spy who had attempted to blow up the ship was still on board. Indeed, as “Number One,” otherwise the first lieutenant, was addressing them a great column of water rose from an explosion deep below the surface, and much of it fell heavily on deck.

Another thorough search was made into every corner of the vessel, whereupon the stranger in uniform was at last discovered in one of the stokeholds. Two stokers rushed across to seize him, but with a quick movement he felled both with an iron bar. Then he ran up the ladder with the agility of a cat, and sped right into the arms of Ella and Kennedy.

“Curse you—I was too late!” he shrieked in fierce anger, on recognising them, and then seeing all retreat cut off, he suddenly sprang over the side of the vessel, intending, no doubt, to swim ashore.

At once the pinnace went after him, but in the darkness he could not be discovered, though the searchlights began to slowly sweep the dark swirling waters.

That he met a well-deserved fate, however, was proved by the fact that at dawn next day his body was picked up on the other side of the bay. Yet long before, Theodore Drost, suspecting that something was amiss by his fellow spy’s non-return, had left by train for London.

Seymour Kennedy was next day called to the Admiralty and thanked for his keen vigilance, but he only smiled and kept a profound secret the active part played by his particular friend, the popular actress—Miss Stella Steele.

Chapter Two.

The Great Tunnel Plot.

“There! Is it not a very neat little toy, my dear Ernst?” asked Theodore Drost, speaking in German, dressed in his usual funereal black of a Dutch pastor, as everyone believed him to be.

Ernst Ortmann, the man addressed, screwed up his eyes, a habit of his, and eagerly examined the heavy walking-stick which his friend had handed to him.

It was a thick bamboo-stump, dark-brown and well-polished, bearing a heavy iron ferrule.

The root-end, which formed the bulgy knob, the wily old German had unscrewed, revealing in a cavity a small cylinder of brass. This Ortmann took out and, in turn, unscrewed it, disclosing a curious arrangement of cog-wheels—a kind of clockwork within.

“You see that as long as the stick is carried upright the clock does not work,” Drost explained. “But,”—and taking it from his friend’s hand he held it in a horizontal position—“but as soon as it is laid upon the ground, the mechanical contrivance commences to work. See!”

And the man Ortmann—known as Horton since the outbreak of war—gazed upon it and saw the cog-wheels slowly revolving.

“By Jove!” he gasped. “Yes. Now I see. What a devilish invention it is! It can be put to so many uses!”

“Exactly, my dear friend,” laughed the supposed Dutch pastor, crossing the secret room in the roof of his house at Barnes.

It was afternoon, and the sunlight streaming through the skylight fell upon the place wherein the bomb-makers worked in secret. The room contained several deal tables whereon stood many bottles containing explosive compounds, glass retorts, test-tubes, and glass apothecaries’ scales, with all sorts of other apparatus used in the delicate work of manufacturing and mixing high-explosives.

“You see,” Drost went on to explain, as he indicated a large mortar of marble. “I have been treating phenol with nitric acid and have obtained the nitrate called trinitrophenol. I shall fill this case with it, and then we shall have an unsuspicious-looking weapon which will eventually prove most useful to us—for it can be carried in perfect safety, only it must not be laid down.”

Ortmann laughed. He saw that his friend’s inventive mind had produced an ingenious, if devilish, contrivance. He had placed death in that innocent-looking walking-stick—certain death to any person unconscious of the peril.

Indeed, as Ortmann watched, his friend carefully filled the cavity in the brass cylinder with the explosive substance, and placed within a very strong detonator which he connected with the clockwork, winding it to the full. He then rescrewed the cap upon the fatal cylinder, replacing it in the walking-stick and readjusting the knob, which closed so perfectly that only close inspection would reveal anything abnormal in the stick.

“The other stuff is there already, I suppose?”

“I took it down there the night before last in four petrol-tins.”

“The new stuff?”

“Yes. It is a picric acid derivative, and its relative force is twice as great as that of gun-cotton,” was the reply of the grey-haired man. He spoke with knowledge and authority, for had he not been one of the keenest explosive experts in the German arsenal at Spandau before he had assumed the rôle of the Dutch pastor in England?

“It will create some surprise there,” remarked Ortmann, with an evil grin upon his sardonic countenance. “Your girl knows nothing, I hope?”

“Absolutely nothing. I have arranged to carry out our plans as soon as possible, to-morrow night, or the night after. Bohlen and Tragheim are both assisting.”

“Excellent! I congratulate you, my dear Drost, upon your clever contrivance. Truly, you are a good son of the Fatherland, and I will see that you receive your due and proper reward when our brave brothers have landed upon English soil.”

“You are the eyes and brains of Germany in England,” declared Drost to his friend. “I am only the servant. You are the organiser. Yours is the Mysterious Hand which controls, and controls so well, the thousands of our fellow-Teutons, all of whom are ready for their allotted task when the Day of Invasion comes.”

“I fear you flatter me,” laughed Mr Horton, whom none suspected to be anything else than a patriotic Englishman.

“I do not flatter you. I only admire your courage and ingenuity,” was the quiet reply.

And then the two alien enemies, standing in that long, low-ceilinged laboratory, containing as it did sufficient high-explosives to blow up the whole of Hammersmith and Barnes, bent over the long deal table upon which stood a long glass retort containing some bright yellow crystals that were cooling.

Theodore Drost, being one of Germany’s foremost scientists, had been sent to England before the war, just as a number of others had been sent, as an advance guard of the Kaiser’s Army which the German General Staff intended should eventually raid Great Britain. Truly, the foresight, patience, and thoroughness of the Hun had been astounding. The whole world’s history contained nothing equal to the amazing craft and cunning displayed by those who were responsible for Germany’s Secret Service—that service known to its agents under the designation of “Number Seventy, Berlin.”

It was fortunate that there was hardly a person in the whole of London who knew of the relationship between Stella Steele, the clever revue artiste, whose songs were the rage of all London and whose photographs were in all the shop-windows, and the venerable Dutch pastor. With his usual craft, Drost, knowing how thoroughly English was his daughter, had always posed to her as a great admirer of England and English ways. To judge by his protestations, he was a hater of the Kaiser and all his Satanic works.

If, however, Ella—to give Stella her baptismal name—could have looked into that long, low attic, which her father always kept so securely locked, she would have been struck by the evil gloating of both men.

Ortmann—whom she always held in suspicion—had conceived the plot a month ago—a foul and dastardly plot—and old Drost, as his paid catspaw, was about to put it into execution forthwith.

Next night, just about half-past ten, Stella Steele gay, laughing, with one portion of her lithe body clothed in the smartest of ultra costumes by a famous French couturière , the remainder of her figure either silk-encased or undraped, bounded off the stage of the popular theatre near Leicester Square, and fell into the arms of her grey-haired dresser.

It was Saturday night, and the “house,” packed to suffocation, were roaring applause.

“Lights up!” shouted the stage-manager, and Stella, holding her breath and patting her hair, staggered against the scenery, half-fainting with exhaustion, and then, with a fierce effort, tripped merrily upon the stage and smilingly bowed to her appreciative and enthusiastic audience.

The men in khaki, officers and “Tommies,” roared for an encore. The revue had “caught on,” and Stella Steele was the rage of London. Because she spoke and sang in French just as easily as she did in English, her new song, in what was really a very inane but tuneful revue—an up-to-date variation of musical comedy—had already been adopted in France as one of the marching songs of the French army.

From paper-seller to Peer, from drayman to Duke: in the houses of Peckham and Park Lane, in Walworth and in Wick, the world hummed, sang, or drummed out upon pianos and pianolas that catchy chorus which ran:

Dans la tranchée...
La voilà, la joli’ tranche:
Tranchi, trancho, tranchons le Boche;
La voilà, la joli’ tranche aux Boches,
La voilà, la joli’ tranche!

As she came off, a boy handed her a note which she tore open and, glancing at it, placed her hand upon her chest as though to stay the wild beating of her heart.

“Say yes,” was her brief reply to the lad, who a moment later disappeared.

She walked to her dressing-room and, flinging herself into the chair, sat staring at herself in the glass, much to the wonder of the grey-haired woman who dressed her.

“I’m not at all well,” she said to the woman at last. “Go and tell Mr Farquhar that I can’t go on again to-night. Miss Lambert must take my place in the last scene.”

“Are you really ill, miss?” asked the woman eagerly.

“Yes. I’ve felt unwell all day, and the heat to-night has upset me. If I went on again I should faint on the stage. Go and tell Mr Farquhar at once.”

The woman obeyed, whereupon Stella Steele commenced to divest herself rapidly of the rich and daring gown. Her one desire was to get away from the theatre as soon as possible.

Mr Farquhar, the stage-manager, came to the door to express regret at her illness, and within a few minutes Miss Lambert, the understudy, was dressing to go on and fulfil her place in the final scene.

Her car took her home to the pretty flat in Stamfordham Mansions, just off Kensington High Street, where she lived alone with Mariette her French maid, and there, in her dainty little drawing-room, she sat silent, almost statuesque, for fully five minutes.

“Is it possible?” she gasped. “Is it really possible that such a dastardly plot is being carried out!” she murmured in agitation.

Her little white hands clenched themselves, and her pretty mouth grew hard. She was sweet and charming, without any stage affectations. Yet, when she set herself to combat the evil designs of her enemy-father she was not a person to be trifled with—as these records of her adventures will certainly show.

“I wonder if Seymour can have been misled?” she went on, rising from her chair as she spoke aloud to herself. “And yet,” she added, “he is always so level-headed!”

Mariette—a slim, dark-eyed girl—entered with a glass tube of solidified eau-de-Cologne which she rubbed upon her mistress’s brow, and then Ella passed into her own room and quickly dismissed the girl for the night.

As soon as Mariette had gone she flung off her dress and took another from her wardrobe, a rough brown tweed golfing-suit, and put on a close-fitting cloth hat to match. Then, getting into a thick blanket-coat, she pulled on her gloves and, taking up a small leather blouse-case, went out, closing the door noiselessly after her.

At nine o’clock on the following evening Ella Drost descended in the lift from the second floor of the Victoria Hotel, in Sheffield, and, wearing her blanket-coat, went to the station platform and bought a ticket to Chesterfield—the town with the crooked spire.

Half-an-hour later she walked out into the station yard where she found her lover, the good-looking Flight-Commander, awaiting her in a big grey car. He no longer wore uniform, but was in blue serge with a thick brown overcoat.

“By Jove, Ella!” he exclaimed in welcome, as he grasped her hand. “I’m jolly glad you’ve come up here! There’s a lot going on. You were perfectly correct when you first hinted at it. I’ve been watching patiently for the past month. Hop in; we’ve no time to lose.”

Next second, Ella was in the seat beside her lover, and the powerful car moved off down the Arkwright Road, a high-road running due eastward, till they joined another well-kept highway which, in the pale light, showed wide and open with its many lines of telegraphs—the road to Clowne.

On through the falling darkness they travelled through Elmton and up the hill to Bolsover, where they suddenly turned off to the left and, passing down some dark, narrow lanes, with which Kennedy was evidently familiar, they at last pulled up at the corner of a thick wood.

“Now,” he said, speaking almost for the first time, and in a low voice, “we’ll have to be very careful indeed.”

He had shut off his engine and switched off his lamps.

“We ought to make quite certain to-night that we are not mistaken,” she said.

“That is my intention,” was her lover’s reply, and then she flung off her coat and crossed the stile, entering the wood after him. He had a pocket flash-lamp, and ever and anon threw its rays directly upon the ground so that they could see the path. The latter was an intricate one, for twice they came to cross-paths, and in both cases Kennedy selected one without hesitation.

At last, however, they began to move down the hill more cautiously, conversing in low whispers, and showing no light until they at last found themselves in the grounds attached to a large, low-built country house, lying in the valley.

“Ortmann is living here as Mr Horton,” Kennedy whispered. “They told me in the village that he took the house furnished about three months ago, from a Major Jackson, who is at the front.”

“But why is he living down here—in a house like this?” she asked.

“That’s just what we want to discover. Many Germans have country houses in England for some mysterious and unknown reason.”

Kennedy, glancing at his luminous wrist-watch, noted that it was nearly two o’clock in the morning. From where they stood at the edge of the wood the house was plainly visible, silhouetted on the other side of a wide lawn.

No light showed in any of the windows, and to all appearances the inmates were asleep.

As the pair stood whispering, a big Airedale suddenly bounded forth, barking angrily as a preliminary to attacking them.

It was an exciting moment. But in that instant Ella recognised the bark as that of her father’s dog.

“Jack!” she said, in a low voice of reproof. “Be quiet, and come here.”

In a moment the dog, which Drost had evidently lent to his friend Ortmann as watch-dog, bounded towards his mistress and licked her hand.

It was evident that the occupiers of the lonely place did not desire intruders.

Fearing lest the barking of “Jack” might have alarmed the inmates, they remained silent for a full quarter-of-an-hour, and then again creeping beneath the shadows of the hedges and trees, they managed to cross the lawn and the gravelled path, until they stood together beneath the front of the house.

“Listen!” gasped Kennedy, grasping the girl’s arm. “Do you hear anything?”

“Yes—a kind of muffled crackling noise.”

“That’s a wireless spark!” her lover declared. “So they have wireless here!”

Creeping along, they passed the main entrance and gained the other side of the house where, quite plainly, there could be heard the whir of a dynamo supplying the current.

But though Kennedy’s keen eyes searched for aerial wires, he could discover none in that dim light, the moon having now disappeared entirely. So he concluded that they were so constructed that they could be raised at night and lowered and concealed at daybreak, or perhaps even disguised as a portion of wire fencing.

“As the wireless is working—sending information to the enemy without a doubt—then our friend Ortmann is most probably at home,” whispered the flying-man. “As the motor is still running it will drown any noise, and we might get inside without being heard. Are you ready to risk it?”

“With you, dear, I’ll risk anything that may be for my country’s benefit,” she declared. Then he pressed her soft hand in his, stooping till his lips met hers.

As they stood there in that single blissful moment, there came the sound of a train suddenly emerging from a long tunnel in the side of the hill in the near vicinity, and with the light of the furnace glaring in the darkness it sped away eastward. Its sound showed it to be a goods train—one of the many which, laden with munitions from the Midlands, went nightly towards the coast on their way to the British front.

Only then did they realise that the railway-line ran along the end of the grounds, and that the mouth of the great G— Tunnel was only five hundred yards or so from where they stood. Kennedy took from his pocket a small jemmy in two pieces, which he screwed together, and then began to examine each of the French windows which led on to the lawn. All were closed, with their heavy wooden shutters secured.

The shutters of one, however, though closed, had, he saw by the aid of his flash-lamp, not been fastened. The dog, Jack, following his mistress, was sniffing and assisting in the investigation.

Examining the long window minutely, they saw that it had been closed hurriedly and, hence, scarcely latched. The room, too, was in darkness.

Suddenly, just as Kennedy was about to make an attempt to enter, the electric light was switched on within the room, and the pair had only time to slip round the corner of the house, when the French window opened, and four men stepped forth upon the lawn, conversing in whispers as they walked on tiptoe together across the gravel on to the grass.

“I wonder what’s up!” whispered Kennedy to Ella. “Let us follow and see.”

This they did, keeping always in the dark shadows, and retracing their footsteps to the edge of the wood close to where the railway ran.

As they watched they saw that, having crossed the lawn, the four men entered a meadow adjoining, and they then recognised the figures of Drost and Ortmann with two strangers. They all walked straight to the corner where stood an old cow-shed, and into this they all four disappeared.

For a full half-hour they remained there, Kennedy and his well-beloved crouching beneath a bush in wonder at what there could be in the cow-shed to detain them so long.

The shed was at the base of a high wooded hill. Away, at some distance on the left, the railway-line entered the great tunnel which pierced the hill, and through it ran one of the most important railways from the Midlands to the East Coast.

The reason of their long absence in that tumbledown cow-shed was certainly mysterious. The lovers strained their ears to listen, but no sound reached them.

“Very curious!” whispered Kennedy. “What, I wonder, should detain them so long? There is some further mystery here, without a doubt. Something of interest is in progress.”

Suddenly, all four men emerged from the shed laughing and chatting in subdued tones. Drost was carrying his hat in his hand.

They passed within ten yards of the lovers, and as they went by they overheard Drost say in German: “To-morrow night at 11:30 a heavy munition train will come through the tunnel. Then we shall see!”

And at his words his three companions laughed merrily as they walked back to the house.

Kennedy and the popular revue artiste—the girl whose name was as a household word, and whose songs were sung everywhere—crouched in silence watching the men until they had disappeared through that long French window opening on to the lawn.

Then, when they were alone, Kennedy said in a low voice:

“There’s more going on here, Ella, than we at first anticipated—much more! I wonder what secret that old shed contains—eh?”

“Let’s investigate!” the girl beside him suggested eagerly.

Five minutes later they emerged from the shadow, and hurrying quickly across the grass, entered the old tumbledown shed, whereupon Kennedy switched on his electric torch, when there became revealed a wide hole in the ground, which sloped away steeply in the darkness.

“Hulloa! Why, here’s a tunnel!” exclaimed Kennedy in surprise. “They’ve been down there, evidently! I wonder where it leads to?”

Then, as they both glanced around, they saw a thin, twisted electric cable containing two wires which led from a cigar-box on the ground in a corner away down into the tunnel. Kennedy lifted the lid of the box, and within found an electric tapping-key with ebonite base and two small dry cells for the supply of the current.

“Now what can this mean, I wonder? Some devil’s work here, without a doubt!” he said. “Let us ascertain.”

Together the pair carefully descended into the narrow tunnel that had been driven into the side of the hill, evidently by expert hands, for its roof had been shored up along the whole length with trees cut from the wood. Away along the narrow passage they groped, finding it so low that they were compelled to bend and creep forward in uncomfortable positions until they came to a sudden turn.

Whoever had constructed it had also succeeded—as was afterwards found—in cleverly disguising the great heap of earth excavated. He had also probably misread his bearings, for at one point the subterranean gallery went away at right angles for about fifty yards, until there—where the atmosphere was heavy and oppressive because of lack of ventilation—stood several petrol-tins. To one of them the end of the cable leading from the unsuspicious cow-shed had been attached.

As they stood staring at the petrol-tins a sudden roar slowly approaching sounded directly overhead—a heavy rumble of wheels. Then it died away again.

“Hark!” gasped Ella. “Isn’t that a train? Why, we are directly under the railway-line running through the tunnel.”

“Yes, dear. A touch upon that key up in the shed and we should be blown out of recognition, and the tunnel, one of the most important on the line of railway communication running east and west across England, would be blocked for months.”

“That is what those devils intend!” Ella declared. “How can we frustrate them?”

Seymour Kennedy reflected for a few seconds, holding his torch so that its rays fell upon those innocent-looking petrol-tins at the end of the cunningly contrived sap. Then he took up one of them and carrying it said:

“Let’s get back, dear. We know the truth now.”

“It is evident that they intend to blow in the tunnel from below,” declared Ella, as they crept back along the narrow gallery.

“Without a doubt,” was her lover’s reply. “Mr Horton, as he is known, took the house with but one object—namely, to cut the railway-line to the coast—the line over which so much war material for the front goes nightly. Truly, the Hun leaves nothing to chance.”

“And my father is actually assisting in this dastardly work?”

“I’m afraid he is, darling. But so long as we remain wary and watchful, I hope we may be able to combat the evil activities of these assassins.”

“I’m ready to help you always, as you know,” was the girl’s ready reply. “But it grieves me that father is so completely German in his actions.”

“It is but natural, Ella. He is a German. If he were English, and lived secretly in Germany, he would act as an Englishman. All enemy aliens should have been interned long ago.”

Ever and anon, on their way back to the opening, they both stumbled upon the wire, while Seymour, carrying the petrol-tin, evidently filled with some heavy explosive, followed his well-beloved, who held the torch.

At last they emerged from the close atmosphere of the long, tortuous gallery that had been secretly driven to a point exactly beneath the railway-line in the very heart of the hill, and once again stood upright in the shed. Their clothes were muddy, and their hands and faces were besmeared with mud.

At last Kennedy put down the square heavy tin, the cap of which he very carefully unscrewed, and then examined it by aid of his torch, smelling it critically.

Taking from his pocket a strong clasp-knife he went back into the tunnel again for about fifty yards. With a swift cut he severed the lead which led away to the concealed tins of explosive, and bringing it back with him to the shed, took the severed end, unravelled the silk insulation of both wires, bared them by scraping them thoroughly with his knife, and with expert hand attached them to a detonator which he had taken from the tins concealed at the end of the gallery.

Having done this he put the detonator into the opening of the petrol-tin which, with its wire lead, he afterwards carefully concealed behind a heap of straw in the corner. He had taken care to replace the cable leading from the cigar-box exactly as he had found it, therefore, to the eye, it looked as though nothing had been touched. The cable ran into the underground passage, it was true, but it returned back again into the cow-shed, and into the tin of high-explosive.

Kennedy, who knew something of mining, had noticed that half-way along the working a quantity of earth had been left for the purpose of tamping the gallery, in order that the force of the explosion should go upward, and not come back along the subterranean passage. Before the Kaiser’s secret agents exploded the mine they would, no doubt, fill up the gallery at that point before completing the electric circuit.

It was evident that on that night the four men had made a final inspection before exploding the mine.

Therefore, quite confident in what they had achieved, Ella and her lover crept back, and away through the wood to where they had left the car.

At six o’clock on the following morning, the Victoria Hotel in Sheffield being always open, Ella entered alone, and ascended to her room.

Next evening at half-past seven she met her lover again in the Ecclesall Road, and he drove her out in the car away through Eckington and Clowne, to the wood from which they had watched on the previous night.

The weather was muggy and overcast, with low, heavy clouds precursory of a thunderstorm.

There was plenty of time. The attempt would probably be made at half-past eleven when the munition train passed through, it being intended to explode the whole train as well as the mine in the heart of the tunnel, so as to produce a terrific upheaval by which the tunnel would be blocked for, perhaps, a mile.

Arrived at the edge of the wood, in sight of the lawn and house beyond, soon after ten o’clock, the lovers sat together upon a fallen tree conversing in whispers, and awaiting the result of the counterplot.

They were, however, in ignorance of what was transpiring within the house.

Truth to tell, Ortmann and Drost were at that moment in one of the servants’ bedrooms upstairs, which had been cleared out, and where, upon a long table, stood a complete wireless set both for receiving and transmission.

“That fellow Kennedy is here !—and with my girl Ella!” gasped old Drost, who had just come into the room. “I’ve been across to the wood. They’re actually here!”

“ Kennedy here !” exclaimed Ortmann, his face pale in an instant. “How could he possibly know?”

“Well, he’s here! What shall we do?”

Ortmann stood for a few moments reflecting deeply.

Slowly an evil, sinister grin overspread his countenance.

“Your girl,” he said in German, in a deep voice. “She is your daughter. You wish to protect her—eh?”

“No, she’s English. We are Germans.”

“Excellent. I knew that you were a good Prussian. Then I may act—eh?”

“Entirely as you wish. We must get rid of these watch-dogs,” snarled the old man in a venomous voice.

Ortmann, without further word, descended the stairs and entered the dining-room wherein sat two men, Germans, naturalised as British subjects, by name Bohlen and Tragheim.

To the first-named he gave certain and definite instructions, these being at once carried out.

Kennedy and Ella, both, of course, quite unconscious that their presence had been discovered by the wily Drost, saw a tall man, a stranger, carrying a thick stick, cross the lawn to the gate which gave entrance to the wood, and watched how he remained there for about ten minutes, while presently there emerged a second figure, who crossed to the cow-shed wherein the electric tapping-key remained concealed.

Kennedy glanced at his wrist-watch.

The munition train was almost due to enter the tunnel, therefore the stranger Tragheim, one of Ortmann’s poor, miserable dupes, had been sent forward to depress the key as soon as he heard the second bell ring in the signal-box at the exit of the tunnel—all the signal bells being distinctly heard in the night from the door of the shed.

The ringing of that second bell would announce that the train was passing over the exact point in the line under which the mine had been laid.

The man Bohlen, seeing his companion come out, moved away from the gate across the lawn back to the house, whereupon Kennedy crept up to the spot where the German had been standing, and whence they could obtain a good view of the shed from which the dastardly attempt was to be made.

Beside the gate they found a walking-stick—a thick one made of bamboo.

“That fellow has forgotten his stick,” remarked Kennedy, taking it up, all unconscious of the peril.

From one of the darkened windows of the house Ortmann was watching his action, and chuckled.

Of a sudden, however, a fierce blood-red flash lit up the whole country-side, and with a deafening roar, the shed was hurled high into the air, together with the shattered remains of the man who had pressed the key.

Instead of exploding the mine under the railway tunnel, as was intended, he had exploded the tinful of picric acid derivative which Kennedy had concealed beneath the straw!

Then, a few seconds later, the heavy train laden with munitions for the British front emerged from the tunnel in safety, its driver all unconscious of the desperate attempt that had been made by the enemy in our midst.

Kennedy, having witnessed the consummation of his well-laid plan to blow up any conspirator who touched the key, cast the walking-stick to the ground and, taking Ella’s arm, retraced his steps through the woods.

But they had not gone far ere a second explosion, a sharp concussion which they felt about them, came from somewhere behind them.

“Funny!” he remarked to his well-beloved. “I wonder what that second noise was, dearest?”

“I wonder,” said Ella, and they both hurried back to their car.

Chapter Three.

The Hyde Park Plot.

Two men sat in a big, handsome dining-room in one of the finest houses in Park Lane. One was Theodore Drost, dressed in his usual garb of a Dutch pastor. A look of satisfaction overspread his features as he raised his glass of choice Château Larose.

Opposite him at the well-laid luncheon table sat his friend, Ernst Ortmann, alias Horton, alias Harberton, the super-spy whose hand was—if the truth be told—“The Hidden Hand” upon which the newspapers were ever commenting—that secret and subtle influence of Germany in our midst in war-time.

Count Ernst von Ortmann was a very shrewd and elusive person. For a number of years he had been a trusted official in the entourage of the Kaiser, and having lived his early life in England, being educated at Oxford, he was now entrusted with the delicate task of directing the advance guard of the German army in this country.

Two years before the war Mr Henry Harberton, a wealthy, middle-aged English merchant from Buenos Ayres, had suddenly arisen in the social firmament in the West End, had given smart dinners, and, as an eligible bachelor, had been smiled upon by many mothers with marriageable daughters. His luncheon-parties at the Savoy, the Ritz, and the Carlton were usually chronicled in the newspapers; he was financially interested in a popular revue at a certain West End theatre, and the rumour that he was immensely wealthy was confirmed when he purchased a fine house half-way up Park Lane—a house from which, quite unsuspected, radiated the myriad ramifications of Germany’s spy system.

With Henry Harberton, whose father, it was said, had amassed a huge fortune in Argentina in the early days, and which he had inherited, money was of no account. The fine London mansion was sombre and impressive in its decoration. There was nothing flamboyant or out-of-place, nothing that jarred upon the senses: a quiet, calm, and restful residence, the double windows of which shut out the sound of the motor-’buses and taxis of that busy thoroughfare where dwelt London’s commercial princes. Surely that fine house was in strange contrast to the obscure eight-roomed one in a long, drab terrace in Park Road, Wandsworth Common, where dwelt the same mysterious person in very humble and even economical circumstances as Mr Horton, a retired tradesman from the New Cross Road.

As Ortmann sat in that big dining-room in Park Lane, a plainly decorated apartment with dead white walls in the Adams style, and a few choice family portraits, his friend, Drost, with his strange triangular face, his square forehead and pointed grey beard, presented a picture of the true type of Dutch pastor, in his rather seedy clerical coat and his round horn-rimmed spectacles.

The pair had been discussing certain schemes to the detriment of the English: schemes which, in the main, depended upon the crafty old Drost’s expert knowledge of high-explosives.

“Ah! my dear Count!” exclaimed the wily old professor of chemistry in German, as he replaced his glass upon the table. “How marvellously clever is our Emperor! How he befooled and bamboozled these silly sheep of English. Listen to this!” and from his pocket-book he drew a large newspaper cutting—two columns of a London daily newspaper dated Wednesday, October 28, 1908.

“What is that?” inquired the Kaiser’s arch-spy, his eyebrows narrowing.

“The interview given by the Emperor to a British peer in order to throw dust into the eyes of our enemies against whom we were rapidly preparing. Listen to the Emperor’s clever reassurances in order to gain time.” Then, readjusting his big round spectacles, he glanced down the columns and read in English the following sentences that had fallen from the Kaiser’s lips: “You English are mad, mad, mad as English hares. What has come over you that you are so completely given over to suspicions unworthy of a great nation? What more can I do than I have done? My heart is set upon peace, and it is one of my dearest wishes to live on the best of terms with England. Have I ever been false to my word? Falsehood and prevarication are alien to my nature. My actions ought to speak for themselves, but you listen not to them, but to those who misinterpret and distort them. This is a personal insult, which I feel and resent!”

Drost replaced the cutting upon the table, and both men burst into hilarious laughter.

“Really, in the light of present events, those printed words must cause our dear friends, the English, considerable chagrin,” declared Ortmann.

“Yes. They now see how cleverly we have tricked them,” said Drost with a grin. “That interview gave us an increased six years for preparation. Truly, our Emperor is great. He is invincible!”

And both men raised their tall Bohemian glasses in honour of the Arch-Murderer of Europe.

That little incident at table was significant of the feelings and intentions of the conspirators.

“Your girl Ella is still very active, and that fellow Kennedy seems ever-watchful,” Ortmann remarked presently in a decidedly apprehensive tone. “I know, of course, that your daughter would do nothing to harm you personally; but remember that Kennedy is a British naval officer, and that he might—from patriotic motives—well—”

“Kill his prospective father-in-law—eh?” chimed in the Dutch pastor, with a light laugh.

The Count hesitated for a second. Then he said:

“Well, perhaps not exactly kill you, but he might make things decidedly unpleasant for us both, if he got hold of anything tangible.”

“Bah! Rest assured that he’ll never get hold of anything,” declared Drost. “I’ve had him out to Barnes to dinner once or twice lately, but he’s quite in the dark.”

“Are you absolutely certain that he knows nothing of what is in progress in your laboratory upstairs!” queried Ortmann. “Are you absolutely certain that Ella has told him nothing?”

“Quite—because she herself knows nothing.”

“If she knows nothing, then why are we both watched so closely by Kennedy?” asked Ortmann dubiously.

“Bah! Your fancy—mere fancy!” declared the professor of chemistry. “I know you’ve been unduly suspicious for a long time, but I tell you that Ella and her lover are far too much absorbed in their own affairs to trouble about our business.” Ortmann shrugged his shoulders. He did not tell his friend Drost the true extent of his knowledge, for it was one of his main principles never to confide serious truths to anybody. By that principle he had risen in his Emperor’s service to the high and responsible position he now occupied—the director of The Hidden Hand.

As such, he commanded the services of many persons of both sexes in the United Kingdom. Some were persons who, having accepted German money or German favours in the pre-war days, were now called upon to dance as puppets of Germany while the Kaiser played the tune. Many of them, subjects of neutral countries, had been perfectly friendly to us, but since the war the relentless thumbscrew of blackmail had been placed upon them by Ernst von Ortmann, and they were compelled to do his bidding and act against the interests of Great Britain.

Over the heads of most of them, men and women—especially the latter—the wily Ortmann and his well-organised staff held documentary evidence of such a damning character that, if handed to the proper quarter, would either have caused their arrest and punishment, or, in the case of the fair sex, cause their social ostracism. Hence Ortmann held his often unwilling agents together with an iron hand which was both unscrupulous and drastic. Woe betide either man or woman who, having accepted Germany’s good-will and favours before the war, now dared to refuse to do her dirty work.

Truly, the Hidden Hand was that of the “mailed-fist” covered with velvet, full of double cunning and irresistible influence in quite unsuspected quarters.

Old Theodore Drost was but a pawn in Germany’s dastardly attack upon England, but a very valuable one, from his intimate knowledge of explosives. Moreover, as an inventor of death-dealing devices, he certainly had no equal in Europe.

In order to discuss in secret a daring and terrible plot, the pair had lunched in company at Park Lane.

At that same hour, on that same day, Flight-Commander Seymour Kennedy, in his naval uniform with the “pilot’s wings,” was on leave from a certain air-station on the South-East coast, and was seated opposite Ella Drost in the Café Royal, in Regent Street, discussing a lobster salad tête-à-tête .

It was one of the favourite luncheon places of Drost’s daughter.

The revue in which she had been appearing and in which, by the way, Ortmann was financially interested in secret, had finished its season, and the theatre had closed its doors for the summer. Consequently Ella had taken a tiny riverside cottage near Shepperton-on-Thames, though she still kept open her pretty flat in Stamfordham Mansions, her faithful French maid, Mariette, being in charge.

“You seem worried, darling,” Kennedy whispered, as he bent across the table to her. “What’s the matter?”

“I’ve already told you.”

“But you really don’t take it seriously, do you?” asked the well-known air-pilot. “Surely it’s only a mere suspicion.”

“It is fortunate that I succeeded in obtaining for you an impression of the key of the laboratory,” was the girl’s reply.

“Yes. It was. Your father never dreams that we know all that is in progress there. It’s a real good stunt of yours to keep in with him, and stay at Barnes sometimes.”

“Well, I’ve told you what I ascertained the night before last. Ortmann was there with the others. There’s a big coup intended—a dastardly blow, as I have explained.”

And in the girl’s eyes there showed a hard, serious expression, as she drew a long breath. It was quite plain to her lover that she was full of nervous apprehension, and that what she had related to him was a fact.

Another deeply-laid plot was afoot, but one so subtle and so daring that Kennedy, with his cheerful optimism and his high spirits, could not yet fully realise its nature.

Ella had, an hour before, told him a very remarkable story.

At first, so extraordinary and improbable had it sounded, that he had been inclined to pooh-pooh the whole affair, but now, amid the clatter and bustle of that cosmopolitan restaurant, the same to-day as in the mid-Victorian days, he began to realise that the impression left upon his well-beloved, by the knowledge she had obtained, had been a distinctly sinister one.

“Well, dearest,” he said, again leaning across the little table-à-deux , “I’ll go into the matter at once if you wish it, and we’ll watch and wait.”

“Yes, do, Seymour,” exclaimed the girl anxiously. “I’ll help you. There is a deeply-laid plot in progress. Of that I’m quite certain—more especially because Ortmann came to see dad yesterday morning and went to see him again to-day.”

“You overheard some of their conversation—eh?”

“I did,” was her open response. “And for that reason I am so full of fear.”

At nine o’clock that same night, in accordance with an appointment, Ella Drost stood upon the whitewashed kerb in Belgrave Square, at the corner of West Halkin Street.

Darkness had already fallen. The London streets were gloomy because of the lighting order, and hardly a light showed from any house in the Square.

For fully ten minutes she waited until, at last, from out of Belgrave Place, a car came slowly along, and pulled up at the spot where she stood.

In a moment Ella had mounted beside her lover who, next second, moved off in the direction of Knightsbridge.

“It’s rather fortunate that we’ve met here, darling,” were his first words. “Since we were together this afternoon I have been followed continuously. Had I called at Stamfordham Mansions, Ortmann would have had his suspicions confirmed. But I’ve successfully eluded them, and here we are.”

“I know—I feel sure that Ortmann suspects us. Why does he live as Mr Horton over at Wandsworth Common?”

“Because he is so infernally clever,” laughed the air-pilot, in his cheery, nonchalant way.

Neither of them knew, up to that moment, anything more of Mr Henry Harberton, of Park Lane, save reading in the papers of his social distinction. Neither Kennedy nor his charming well-beloved had dreamed that Ortmann, alias Horton, patriotic Britannia-rule-the-Waves Englishman, was identical with that meteoric planet in the social firmament of London, Mr Henry Harberton, whose wealth was such that even in war-time he could give two-guinea-a-head luncheons to his friends at one or other of the half-dozen or so London restaurants which cater for such clients.

Seymour Kennedy was driving the car swiftly, but Ella, nestling beside him, took no heed of the direction in which they were travelling. The night-wind blew cold and he, solicitous of her welfare, bent over and with his left hand drew up the collar of her Burberry.

They were leaving London ere she became aware of it, travelling westward, branching at Hounslow upon the old road to Bath, the road of Dick Turpin’s exploits in the good old days of cocked-hats, powder-and-patches, and three-bottle men.

Passing through Slough, they crossed the river at Maidenhead and again at Henley, keeping on the ever ascending high-road over the Chilterns, to Nettlebed, until they ran rapidly down past Gould’s Grove through Benson, and past Shillingford where, a short distance beyond, he pulled up and, opening a gate, placed the car in a meadow grey with mist.

Afterwards the pair, leaving the high-road, turned into a path which led through the fields down to the river. Reaching it at a point not far from Day’s Lock, they halted.

Before them, between the pathway and the river’s brink, there showed a lighted window obscured by a yellow holland blind, the window of a corrugated iron bungalow of some river enthusiast, the room being apparently lit by a paraffin lamp.

Carefully, and treading upon tiptoe, they crept forward without a sound, and, approaching the square, inartistic window, halted and strained their ears to listen to the conversation in progress within.

Words in German were being spoken. Ella listened, and recognised her father’s voice. Ortmann was speaking, too, while other voices of strangers also sounded.

What Seymour overheard through the thin wood-and-iron wall of the riverside bungalow quickly convinced him that Ella’s suspicions were only too well founded. A desperate conspiracy to commit outrage was certainly being formed—a plot as daring and as subtle as any ever formed by the Nihilists in Russia, or the Mafia in Italy.

The Germans, par excellence the scientists of Europe, were out to win the war by frightfulness, just as thousands of years ago the Chinese won their wars by assuming horrible disguises and pulling ugly faces to bring bad luck upon their superstitious enemies. The Great War Lord of Germany, in order to save his throne and substantiate his title of All-Highest, had set loose his sorry dogs of depravity, degeneracy, and desolation. And he had planted in our island a clever and unscrupulous crew, headed by Ortmann, whose mission was, if possible, to wreck the Ship of State of Great Britain.

The air-pilot listened to the conversation in amazement. He realised then how Ella had exercised a shrewder watchfulness than he had ever done, although he had believed himself so clever.

Therefore, when she whispered, “Let’s get away, dear, or we may be discovered,” he obeyed her, and crawled off over the strip of gravel to the grass, after which both made their way back to the footpath.

“Well?” asked the popular actress, as they strode along hand in hand to where they had left the car. “What’s your opinion now—eh? Haven’t you been convinced?”

“Yes, darling. I can now see quite plainly that there is a plot on foot which, if we are patriots, you and I, we must scotch, at all hazards.”

“I agree entirely, Seymour,” was the girl’s instant reply. “I tried to warn you a month ago, but you were not convinced. To-day you are convinced—are you not? I am acting only for my dear dead mother’s country, for, strictly speaking, being the daughter of a German, I am an alien enemy.”

About two o’clock one morning, about a week later, the dark figure of a man in a shabby serge suit and golf-cap, treading noiselessly in rubber-shoes, crossed Hammersmith Bridge in the direction of Barnes and, passing along that wide open thoroughfare, paused for a moment outside the house of the Dutch pastor, Mr Drost. Then, finding himself unobserved, he slipped into the front garden and, bending, concealed himself in some bushes.

He had waited there for ten minutes or so, watching the dark, silent house, when, slowly and noiselessly, the front door opened, and next moment Kennedy and Ella were face to face. The latter wore a pretty pale-blue dressing-gown, for she had just risen from bed, she having spent the last two days at her father’s house.

With a warning finger upon her lips, and with a small flash-lamp in her hand, she led her lover up three flights of stairs to the door of that locked room, which she silently opened with her duplicate key.

“Father and the man Hans Rozelaar have been at work here nearly all day,” she whispered, when at last they halted before the long deal table upon which stood Drost’s chemical apparatus.

Kennedy’s shrewd eyes were quick to notice what was in progress in secret.

With some curiosity he took up a tube of tin about a foot long and four inches in diameter. On examining it he saw that through the centre was a second tin tube of about an inch in diameter. Holding it as a telescope towards the light he could see through the inner tubes and noticed that near one end of it a small steel catch was protruding. Further and minute examination revealed that to the catch could be attached a time-fuse already concealed between the inner and outer tubes.

“This is evidently some ingenious form of hand grenade,” whispered Kennedy. “It’s all ready for filling. But why, I wonder, should a tube run through the middle in this way?”

He was pondering with it in his hand, when his gaze suddenly fell upon something else which was lying close to the spot where he found the tin tube.

It was a thin ash walking-stick. On Kennedy taking it up it presented a peculiar feature, for as he grasped it there sounded a sharp metallic click. Then, to his surprise, he discovered that he had inadvertently released a spring in the handle, this in turn releasing four small steel points half-way down the stick.

“Curious!” he whispered to his well-beloved, for Drost was sleeping below entirely unconscious of the intruders in his secret laboratory. “What connection can the stick have with the grenade—if not for the purpose of throwing?”

He therefore placed the inner tube over the little knob of the stick, and found that it just fitted, so that with plenty of play it slid down as far as the projecting points which, after striking the little steel catch which would be connected with the fuse, allowed it to pass over freely and leave the stick.

“Ah! I’ve got it!” he whispered excitedly. “The grenade can be carried in the pocket with perfect safety, until when required it is placed over the handle of the stick and whirled off. As it passes the projections on the stick the time-fuse is set for so many seconds, and the grenade automatically becomes a live one. A very pretty contrivance indeed!—very pretty!” he added with a grin. “This, I must admit, does considerable credit to Ortmann, Drost and Company.”

Ella, who had been standing by, holding the electric torch, stood in wonder at the discovery. Truly, some of her father’s inventions had been diabolical ones.

Kennedy saw that the ash-stick had been finished and was in working order. All was complete, indeed, save the filling of the deadly grenade, the attaching of the fuse, and the painting of the bright tin.

For fully five minutes the air-pilot stood in silence, deeply pondering.

Then, as a sudden idea occurred to him, he said quickly:

“I must take this stick, Ella. I’ll be back again by four o’clock, and will leave it just outside the front door. You take it in, and replace it exactly as we found it.”

He lost no time. In five minutes he had crept from that dark house of mystery and death, and, carrying the stick, returned across Hammersmith Bridge.

At ten minutes to four he was back again in Barnes and had left the suspicious-looking ash-stick against the front door, afterwards going to his rooms to snatch a few hours’ sleep.

Next day happened to be Sunday, but at noon on Monday Mr Merton Mansfield, one of the most active members of the Cabinet, as well as one of the most popular of Cabinet Ministers, presided at the unveiling of a number of captured German guns which had been drawn up in Hyde Park in order that the public might be afforded an opportunity of seeing the trophies of war in Flanders won by British pertinacity and pluck.

Accompanying Merton Mansfield, the people’s idol, the man in whom Great Britain trusted to see that all was well, and who was, at the same time, hated and feared by the Germans, were several other members of the Cabinet.

The crowd outside the wire fence, within which stood the shrouded guns, was a large one, for some patriotic speeches were expected. Ella and Kennedy were among the spectators eagerly watching the movements of a thin-faced, well-dressed, middle-aged man, who wore an overcoat, in the left-hand pocket of which was something rather bulky, and who carried in his hand an ash-stick.

The man’s name was Hans Rozelaar, known to his friends by the English name of Rose. By the fellow’s movements it was plain that he was quite unsuspicious of the presence of the daughter of his fellow-conspirator, Theodore Drost.

Gradually he had worked himself through the crowd until he stood in the front row behind the wire which fenced off the guns with the Cabinet Ministers and their friends, and within ten yards or so of where stood Mr Merton Mansfield.

Kennedy was beside Ella some distance away, watching breathlessly. It had been his first impulse to go to Scotland Yard and reveal what they had discovered, but after due consideration he saw that the best punishment for the conspirators was the one he had devised.

But if it failed? What if that most deadly grenade was exploded in the group of Great Britain’s leaders—the men who were working night and day, and working with all their might and intelligence, to crush the Hun effectively, even though so slowly.

A roar of applause rose from the crowd as Merton Mansfield removed his hat preparatory to speaking. The short, stout, round-faced Cabinet Minister who, in the days of Sir Henry Campbell-Bannerman’s Premiership, had been so unpopular with the working-class, yet who had now come to the forefront as the saviour of our dear old England, smiled with pleasure at his hearty reception.

The little group of England’s greatest men, Cabinet Ministers and well-known politicians, with a sprinkling of men in khaki, clustered round him, as he commenced to address the assembly, to descant upon the heroic efforts of “French’s contemptible little Army,” of their great exploits, of their amazing achievements, and the staggering organisation of Lord Kitchener.

“Here, before you, you have some small souvenirs—some small idea of the weapons which the unscrupulous fiends who are our enemies are using against our gallant troops. They, unfortunately, are not gallant soldiers, these Huns in modern clothing—they are pirates with the skull and crossbones borne upon the helmets of their crack regiments. Yet we shall win—I tell you that we shall win, be the time long or short, be the sacrifice great or small—we shall win because Right, Truth, and God’s justice are with us! And I will here give you a message from the Prime Minister—who would have been here, if it were not for the fact that he is at this moment having audience of His Majesty the King.”

A great roar of applause greeted this announcement, when, suddenly, a loud explosion sounded, startling everyone and causing women to scream.

The lovers, who had kept their eyes upon the man in the overcoat, saw a red flash, and saw him reel and fall to earth with his face blown away.

They had seen how he had placed the grenade over his ash-stick, and how, a second later, he had sharply slung it across from right to left, intending the deadly bomb to land at Mr Merton Mansfield’s feet.

Instead, with its fuse set by the little points of steel protruding from the stick, it had, nevertheless, failed to pass from the stick, because of the small piece of thin wire which Seymour Kennedy had driven through just above the ferrule, on that night when he had afterwards left the stick at old Drost’s front door. His quick intelligence had shown him that the empty grenade had already been tried upon the stick, and that when filled, and the fuse attached, it certainly would not be tested again.

Hans Rozelaar had slung the grenade just as old Theodore Drost had instructed him, but it had remained fast at the end of the stick, and ere he could release it, it had exploded, blowing both his hands off and his features out of all recognition, though, very fortunately, injuring no one else.

“Come, darling. We have surely seen enough!” whispered Seymour Kennedy softly to Ella, as they watched the great sensation caused by the self-destruction of the conspirator, and the hurry of the police towards the dead man. “The Ministers will very soon discover for themselves how narrowly they have escaped.”

And as they both turned away, Ella, looking fondly into her lover’s face, remarked in a low voice: “Yes, indeed, Seymour. They certainly owe their safety to you!”

Chapter Four.

The Explosive Needle.

“Then you suspect that another plot is in progress, Ella?”

“I feel confident of it. The Count is furious at the failure of the conspiracy against Mr Merton Mansfield. He came to see father last night. I did not gather much, as I had to get away to the theatre, but I overheard him suggest that some other method should be tried,” replied Ella Drost.

She was sitting in the dainty little drawing-room of the flat in Stamfordham Mansions, chatting with her airman lover.

“Of course,” he said. “Ortmann and your father were well aware that Merton Mansfield is still the strongest man in the whole Government, a marvellous organiser, and the really great man upon whom Britain has pinned her faith.”

“They mean to work some evil upon him,” the girl said apprehensively. “I’m quite certain of it! Cannot we warn him?”

“I did so. I wrote to him, urging him to take precautions, and declaring that a plot was in progress,” said Kennedy. “I suppose his secretary had the letter and probably held it back in order not to disturb him. Secretaries have a habit of doing that.”

Ella, whose cigarette he had just lit, blew a cloud of blue smoke from her lips, and replied:

“Well, if that’s the case then it is exceedingly wrong. The greatest care should be taken of those who are leading us to victory. Ah! dearest,” she added with a sigh, “you do not know how bitter I feel when I reflect that my own father is a German and, moreover, a most deadly enemy.”

“I know, darling, I know,” the man responded. “That’s the worst of it. To expose the organiser of these conspirators would be to send your own father to prison—perhaps to an ignominious end.”

“Yes. All we can do is to watch closely and thwart their devilish designs, as far as we are able,” the girl said.

“Unfortunately, I’ll have to go back to the air-station to-night, but I’ll try to come up again for the week-end.”

Disappointment overspread the girl’s face, but a second later she declared:

“In that case I shall go and stay with father over at Barnes, and endeavour to discover what is intended.”

Therefore, that night, after her work at the theatre, she went to Theodore Drost’s house at Barnes, instead of returning to the flat at Kensington. As she always kept her room there and her visits seemed to delight old Drost, she was always able to keep in touch with Kennedy and so help to frustrate the evil machinations of her father.

As the days passed she became more than ever confident that another deep-laid plot was in progress. Nor was she mistaken, for, truth to tell, Ortmann was having many long interviews with his clever catspaw, the man who posed as the plain and pious pastor of the Dutch Church, old Theodore Drost.

An incident occurred about a week later which showed the trend of events. The old pastor called one day at that modest, dreary little house close by Wandsworth Common, where Count Ernst von Ortmann, the man who secretly directed the agents of Germany in England, lived as plain Mr Horton whenever he grew tired of his beautiful house in Park Lane. Leading, by the fact of his occupation a dual existence, it was necessary for his nefarious purposes that he should frequently disappear into South London, away from the fashionable friends who knew him as Mr Henry Harberton.

The pair were seated together that evening, smoking and discussing the cause of the failure of Rozelaar and the reason of his death by his own bomb.

“Ah! my dear Theodore,” exclaimed the Count, in German, throwing himself back in the old wicker armchair in that cheaply furnished room. “Your machine was too elaborate.”

“No, you are mistaken, it was simplicity itself,” Drost declared.

“Could anybody have tampered with it, do you think?”

“Certainly not. Nobody knew—nobody saw it except ourselves and Rozelaar,” Drost said.

“And we very nearly blew ourselves up with it during the test. Do you remember?” laughed Ortmann.

“Remember! I rather think I do. It was, indeed, a narrow escape. We won’t repeat it. I’ll be more careful, I promise you!” Drost assured his paymaster. “Yet I cannot guess how Rozelaar lost his life.”

“Well, we need not trouble. His was not exactly a precious life, Theodore, was it? The fellow knew a little too much, so, for us, it is perhaps best that the accident should have happened.”

“It is not the first time that fatal accidents have happened to those who, having served Germany, are of no further use,” remarked Drost grimly.

And at his remark the crafty Count—the man who directed the German octopus in Britain—smiled, but remained silent.

Though Ella, still at Barnes, kept both eyes and ears open during the day—compelled, of course, to go to the theatre each evening—yet she could discover no solid fact which might lead her to find out what was in progress.

The Count came very often over to Barnes, and on two or three occasions was accompanied by a fair-haired young man whose real name was Schrieber, but who had changed it to Sommer, and declared himself to be a Swiss. Indeed, he had forged papers just as old Drost possessed. The fabrication of identification-papers—with photographs attached—became quite an industry in Germany after war had broken out, while many American passports were purchased from American “crooks” and fresh photographs cleverly superimposed.

One afternoon the young man Schrieber called, remained talking alone with Drost for about ten minutes, and then left. Presently the old man entered the drawing-room wherein his daughter was seated writing a letter. In his hand he carried a china vase about fourteen inches high, the dark-blue ornamentation being very similar to a “willow-pattern” plate. It was shaped something like a Greek amphora, and quite of ordinary quality.

“Ella, dear,” said her father, handing her the vase, “I wish you could get one exactly like this. You’ll be able to get it quite easily at one of the big stores in the West End. A friend of mine has a pair, and has broken one.”

“Certainly, dad,” was the girl’s reply. “I’m going out this afternoon, and I’ll take it with me.” That afternoon Ella Drost went to several shops until at last, at one in Oxford Street, she found the exact replica. They were in pairs, and she was compelled to buy both. Later on she took them to Barnes, but before doing so she called in at her own flat and there left the superfluous vase.

Old Drost seemed highly delighted at securing the exact replica of the broken ornament.

“Excellent!” he said. “Excellent! Really, my dear child, I thought that you would have had to get it made. And making things in war-time is such a very long process.”

“I had a little trouble, but I at last got a clue to where they had been bought, and there, sure enough, they had one pair still in stock.”

“Excellent! Excellent!” he grunted, and he carried off both the pattern vase and its companion to his little den where he usually did his writing.

That same evening, while the taxi was at the door to take Ella to the theatre, the Count called.

“Ah! Fräulein!” he cried, as he entered the dining-room where Ella stood ready dressed in her smart coat and hat, as became one who had been so successful in her profession and drew such a handsome salary, much to the envy of her less fortunate fellow-artistes. “Why—you’re quite a stranger—always away at the theatre whenever I call. I took some friends from the club to see you the night before last. That new waltz-song of yours is really most delightful—so catchy,” he added, speaking in German.

“Do you like it?” asked the bright, athletic girl who led such a strange semi-Bohemian life, and was yet filled with constant suspicion concerning her father. “At first I did not like singing it, because I objected to some of the lines. But I see now that everyone seems attracted by it.”

“No, Fraulein Ella!” exclaimed the Count, with his exquisite courtesy. “The public are not attracted by the song, but by your own chic and charm.”

“Now, really, Count,” exclaimed Ella, “this is too bad of you! If one of my stall-admirers had said so I would forgive him. But, surely, you know me too well to think that I care for flattery from you. I have been too long on the stage, I assure you. To me applause is merely part of the show. I expect it, and smile and bow when the house claps. It does not fill me with the least personal pride, I assure you. When I first went on the stage it certainly did. But to-day, after being all these years before the public—”

“All these years!” echoed Ortmann, interrupting her. “Why, you are not much more than twenty now, Ella!”

“And think, I’ve already been twelve years on the stage—a life hard enough, I can tell you!”

“Yes, I know,” remarked the Count. “But you’ll forget all about your friend Commander Kennedy some day, I expect, and marry a wealthy man.”

Ella’s eyebrows contracted for a few seconds.

“Well—perhaps,” she said. “But I may yet marry Mr Kennedy, you know!”

Count Ernst Ortmann smiled—a hard evil expression upon his heavy lips. He held Seymour Kennedy in distinct suspicion.

Indeed, when Ella had gone and he was standing with old Drost in the dining-room, he remarked:

“I still entertain very grave suspicions regarding that fellow Kennedy. Couldn’t you keep Ella away from him? Could not we part them somehow? While they are in love a distinct danger exists. He may learn something at any moment. My information is that he is particularly shrewd at investigations, and he may suspect. If so, then the game might very easily be up.”

“Bah! Do not anticipate any such contretemps . He knows nothing—take that from me. We have nothing whatever to fear in that direction,” Drost assured him. “If I thought so I should very soon take steps to part them.”

“How would you accomplish that?”

Theodore Drost’s narrow face—broad at the brow and narrow at the chin—puckered in a smile.

“It would not be at all difficult,” he said, with a mysterious expression. “I have something upstairs which would very soon effect our purpose and leave no trace—if it were necessary.”

“But it is necessary,” the Count declared.

“One day it may be,” Drost said. “But not yet.”

“Your girl is in love with him, and I suppose you think it a pity to—well, to spoil their romance, even in face of all that Germany has at stake!” remarked the Count, with an undisguised sneer. “Ah, my dear Drost! you pose as a Dutch pastor, but do you not remember our German motto: Der beste prediger ist der Zeit ?” (Time is the best preacher.)

“Yes, yes,” replied the old man with the scraggy beard. “But please rely upon my wits. My eyes are open, and I assure you there is nothing whatever at present to fear.”

“Very well, Drost,” Answered the Count. “I submit to your wider knowledge. But now that the girl has gone, we may as well go upstairs—eh? You’ve, of course, seen in to-night’s paper that Merton Mansfield is to address the munition-makers in the Midlands in a fortnight’s time.”

Old Drost again smiled mysteriously, and said:

“I knew that quite a fortnight ago. Schrieber has been north. He returned only last Tuesday.”

“Did you send him north?”

“I did. He went upon a mission. As you know, I am generally well ahead with any plans I make.”

“Plans! What are they? Really, my dear Theodore, you are a perfect marvel of clever inventiveness!”

Ella’s father shrugged his shoulders, and in his deep guttural German replied:

“I am only doing my duty as a good loyal son of our own Fatherland.”

“Well spoken,” declared the Count. “There is a good and just reward awaiting you after the war, never fear! Our Emperor does not forget services rendered. Let us go upstairs—eh? I am anxious to learn what you suggest.”

The pair ascended the stairs to the carefully locked room in the roof, that long, well-equipped laboratory wherein Theodore Drost spent so many hours daily experimenting in the latest discovered high-explosives. After Drost had switched on the light he carefully closed the door, and then, crossing to a long deal cupboard where hung several cotton overalls to protect his clothes against the splash of acids, he took out his military gas-masks—those hideous devices with rubber mouth-pieces and mica eye-holes, as used by our men at the front.

“It is always best to take precautions,” Drost said, as he handed his companion and taskmaster a helmet. “You may find it a little stifling at first, but it is most necessary.”

Both put on the masks, after which Drost handed the Count a pair of rubber gloves. These Ortmann put on, watching Drost, who did the same.

“It is a good job, Count, that we are alone in the house, otherwise I could do no work. The gas is heavy, and any escaping from here will fall to the basement. One fourteen-thousandth part in air, and the result must be fatal. There is no known antidote. Ah!” he laughed, “these poor, too-confiding English little dream of our latter-day discoveries—scientific discoveries by which we hold all the honours in the game of war.”

“Very well,” grunted the Count. “Let us hope that our science is better than that of our enemies. But I confess that to-day I have doubts. These British have made most wonderful strides—the most amazing progress in their munitions and devices.”

While he spoke old Drost was, with expert hand, mixing certain compounds, grey and bright-green crystals, which he pounded in a mortar. Then, carefully weighing with his apothecary’s scales several grammes of a fine white powder, he added it and, while the Count, still wearing his ugly mask, watched, mixed a measured quantity of water and placed the whole into a big glass retort which was already in a holder warmed by the pale-blue flame of a spirit-lamp.

Suddenly Drost made a gesture to his companion, and while the liquid in the retort was bubbling, he attached to the narrow end of the retort an arrangement of bent glass tube, and proceeded to distil the liquid he had produced.

This product, which fell drop by drop into a long test-tube, was of a bright-blue colour. Drop by drop fell that fatal liquid—fatal because it gave off a poison-gas against which no human being could exist for more than five seconds.

“This,” exclaimed Drost, his voice muffled by his mask, “is the most fatal of any gas that chemical science has yet discovered. It does not merely asphyxiate and leave bad symptoms afterwards, but it kills outright in a few seconds. It is absolutely deadly.”

The room had by that time become filled by a curious orange-coloured vapour—bright-orange—which to Ortmann’s eyes was an extraordinary phenomenon. Had he not worn the protective mask he would have been instantly overwhelmed by an odour closely resembling that of cloves—a terribly fatal perfume, which would sweep away men like moths passing through the flame of a candle.

“Well, my dear Drost,” said the Count, “I know you will never rest until you’ve devised a means of carrying out our plans for the downfall of Merton Mansfield, and certainly you seem to have adopted some measure—deadly though it may be—which is quite in accord with your ingenuity.” He also spoke in a low, stifled voice from within his ugly mask.

Drost nodded, and then into the marble mortar, in which he had mixed his devilish compounds, he poured something from a long blue glass-stoppered bottle, whereupon the place instantly became filled with volumes of grey smoke which, when it cleared, left the atmosphere perfectly clear—so clear, indeed, that both men removed their masks, sniffing, however, at the faint odour of cloves still remaining.

Afterwards the old chemist took from the cupboard a small cardboard box which, on opening, contained, carefully packed in cotton wool, a short, stout, but hollow needle. Attached to it at one end was a small steel box about two inches broad and the same high. The box was perforated at intervals.

“This is the little contrivance of which I spoke,” said Drost gleefully, as he gazed upon it in admiration. “The explosive needle, when filled, and this little chamber, also properly charged, cannot fail to act.”

“I take it, my dear friend, that it will be automatic—eh?” remarked the Count, examining it with interest.

Old Drost smiled, nodded, and replaced his precious contrivance in its box, after which both men left the laboratory, Drost carefully locking the door before descending the stairs to follow his companion.

Both of them took a taxi to the fine house in Park Lane where Ortmann assumed the rôle of society man. At ten o’clock a visitor was ushered in, and proved to be the young man whose real name was Schrieber. Apparently he had just returned from a journey, and had come straight from the station in order to make some secret report to Ortmann.

When the three were closeted together the young German, who passed as a Swiss, produced from his pocket three small photographs showing the interior of a room taken from different angles, but always showing the fireplace.

“Excellent!” declared Drost, as he examined all three prints beneath the strong light. “You have done splendidly.”

“Yes, all is in readiness. I have made friends with the maids, and when I return I shall be welcomed. No breath of suspicion will be aroused. We have now but to wait our time.”

And the three conspirators—men who were working so secretly, yet with such dastardly intent in the enemy’s cause—laughed as they helped themselves to cigars from the big silver box.

Nearly three weeks passed when, one day while Seymour Kennedy was sitting in Ella’s pretty little drawing-room, he accidentally noticed the artistic blue-and-white vase, and remarking how unusual was the shape, his beloved related how it had come into her possession.

Kennedy reflected for a few seconds, his brows knit in deep thought.

“Curious that your father desired to match a vase like this! With what object, I wonder?”

“He told me that he wanted it for a friend.”

“H’m! I wonder why his friend was so eager to match it?” was the air-pilot’s remark. “And, again, why did he send you to buy it, when his friend could surely have done so?”

Ella was silent. That question had never occurred to her.

“I wonder if your father is making some fresh experiment? Have you been to the laboratory lately?” he inquired.

“No, dear.”

“A secret visit there might be worth while,” he suggested. “Meanwhile, the question of this vase excites my curiosity considerably. I can’t help thinking that Ortmann is at the bottom of some other vile trickery. Their failure to kill Merton Mansfield has, no doubt, made them all the more determined to deal an effective coup .”

Some five days later it was announced in the London papers that Mr Merton Mansfield, the man in whom Great Britain placed her principal trust in securing victory, would, on the following Thursday, address a mass meeting of the munition workers in the great Midland town of G—. The object of the meeting was to urge greater enthusiasm in the prosecution of the war, and to induce the workers, in the national cause, to forego their holidays and thus keep up the output of heavy shells and high-explosives.

Seymour Kennedy, who was in the mess at the time, read the paragraph, and then sat pondering.

Next day he induced his commanding officer to give him leave, and he was soon in London making active inquiries. He found that Mr Merton Mansfield had been compelled to decline the invitation of Lord Heatherdale, and had arranged to stay the night at the Central Station Hotel at G—, as he would have to return to London by the first train next morning.

Mr Merton Mansfield was an extremely busy man. No member of the Cabinet held greater responsibility upon his shoulders, and certainly no man held higher and stronger views of British patriotism. Any words from his lips were listened to eagerly, and carefully weighed, not only here, but in neutral countries also. Hence, at this great meeting he was expected to reveal one or two matters of paramount interest, and also make a further declaration of British policy.

On the Tuesday night—two days before the meeting—Flight-Commander Kennedy slept at the Central Hotel in G— and next morning returned to London.

Next night—or rather at early morning—Ella silently opened the front door of her father’s house at Barnes, and her lover slipped in noiselessly, the pair afterwards ascending to the secret laboratory which his well-beloved opened with her duplicate key. Without much difficulty they opened the cupboard and examined the contents of the small cardboard box—discovering the curious-looking needle attached to the little perforated steel box.

“This place smells of cloves—doesn’t it?” whispered Seymour.

“Yes, darling. I’ve smelt the same smell for some days. Father said he had upset a bottle of oil of cloves.”

“This is certainly a most curious apparatus!” Kennedy whispered, holding the needle in his hand. “See, this box is not a bomb. It is perforated to allow some perfume—or, more likely, a poison-gas—to escape. The needle is certainly an explosive one!”

Further search revealed a small clockwork movement not much larger than that of a good-sized watch, together with a small bag of bird’s sand.

Having made a thorough search, they replaced things exactly as they had found them, and then Kennedy crept forth again into the broad thoroughfare called Castelnau.

“Those devils mean mischief again!” he muttered to himself as he hurried across Hammersmith Bridge. “That explosive needle is, I can quite see, a most diabolical invention. Drost surely has the inventive brains of Satan himself!”

At that same hour the young man Schrieber was seated with Ortmann in Park Lane, listening to certain instructions, until at last he rose to go.

“And, remember—trust in nobody!” Ortmann urged. “If you perform this service successfully, our Fatherland will owe you a very deep debt of gratitude—one which I will personally see shall not be forgotten.”

At midday on Thursday Kennedy and Ella left St. Pancras station for G—, arriving there three hours later, and taking rooms at the Central Hotel.

As soon as Ella entered hers, she was astonished to see upon the mantelshelf a pair of the same blue-and-white vases as those her father had asked her to match!

When, ten minutes later, she rejoined Kennedy in the lounge, she told him of her discovery.

“Yes,” was his reply. “They are the same in all the rooms—one of the fads of the proprietor. But,” he added, “you must not be seen here. We don’t know who is coming from London by the next train.”

For that reason Ella retired to her room and did not leave it for some hours, not indeed till her lover came to tell her that all was clear.

By that time Mr Merton Mansfield had arrived, eaten a frugal dinner, and had gone to the meeting.

“That young man Schrieber has arrived also,” Kennedy told her. “He’s never seen me, so he suspects nothing. He has also gone to the meeting, therefore we can go down and have something to eat.”

That night at eleven o’clock Mr Merton Mansfield returned, was cheered loudly by a huge crowd gathered outside the hotel, and waited below chatting for nearly half-an-hour before he retired to his room.

The room was numbered 146—the best room of a suite on the first floor—and to this room the young German, the catspaw of Ortmann, had gone about a quarter past eleven, gaining admission through the private sitting-room next door.

On entering he, quick as lightning, took down one of the vases from the mantelshelf and replaced it by another exactly similar which he drew from beneath the light coat thrown over his arm. Then, carrying the vase with him concealed by his coat, he slipped quickly out again unobserved, not, however, before he had poured into the other vase some bird-sand so as to make them both of equal weight when the maid came to dust them on the morrow. The conspirators left nothing to chance.

In that innocent-looking vase he had brought was one of the most diabolical contrivances ever invented by man’s brain. To the explosive needle the tiny clock had been attached and set to strike at half-past two, an hour when the whole hotel would be wrapped in slumber. The effect of striking would be to explode the needle and thus break a thin glass tube of a certain liquid and set over a piece of sponge saturated by a second liquid. The mixing of the two liquids would produce that terribly deadly poison-gas which, escaping through the perforation, must cause almost instant death to any person sleeping in the room.

Truly, it was a most diabolical death-trap.

Ten minutes later Mr Merton Mansfield, quite unsuspicious, entered the room and retired to bed, an example followed by the assassin Schrieber, who had a room on the same corridor a little distance away.

At nine o’clock next morning Seymour Kennedy, bright and spruce in his uniform, descended to the hall and inquired of the head-porter if Mr Merton Mansfield had left.

“Mr Mansfield is an early bird, sir. He went away to London by the 6:47 train.”

The air-pilot turned upon his heel with a sigh of relief.

Two hours later, however, while seated in the lounge with Ella, prior to returning to London, Kennedy noticed that there was much whispering among the staff. Of the porter he inquired the reason.

“Well, sir,” the man replied, “it seems that a maid on the first floor, on going into one of the rooms this morning, found a visitor dead in bed—Mr Sommer, a Swiss gentleman who arrived last night. The place smells strongly of cloves, and the poor girl has also been taken very ill, for the fumes in the place nearly asphyxiated her.”

Seymour again returned to Ella and told her what had occurred.

“But how did you manage it?” she asked in a low whisper.

“Well, after watching Schrieber put the vase in the room, I entered after him and replaced it by the vase you had bought, afterwards taking the one with the explosive needle to Schrieber’s room and carrying away the superfluous one. The man must have glanced at the pair of vases on his mantelshelf before sleeping, but he, of course, never dreamed that he was gazing upon the infernal contrivance that he had placed in the Minister’s room with his own hand.”

“I see,” exclaimed Ella. “And, surely, he richly deserved his fate!”

The deadly contrivance was found when the room was searched, but the police of G— still regard the affair as a complete and inexplicable mystery.

Chapter Five.

The Brass Triangle.

A bank of dense fog hung over the Thames early on that December morning. The bell of St. Paul’s Church, at Hammersmith, had struck two o’clock when across the long suspension-bridge a tall man in a black waterproof coat and black plush hat walked with a swing, smoking a cigarette, and passed hurriedly out into the straight broad thoroughfare of Castelnau.

For some distance he proceeded, then suddenly he slackened pace, glanced at the luminous watch upon his wrist, and, a few moments later, halted against some railings, and, looking across the road, waited patiently opposite the house occupied by the pious Dutch pastor, the Reverend Theodore Drost.

The house was in darkness, and there was not a sound in the street save the barking of a dog at the rear of a house in the vicinity.

In patience, Flight-Commander Kennedy, for it was he, waited watchfully. He remained for a full quarter of an hour, ever and anon glancing at his watch, until, of a sudden, the front door opposite was opened noiselessly, and he saw the gleam of a flash-lamp.

In a moment he had crossed the road and, ascending the steps, met his well-beloved. As he met her, he thought how strange it all seemed, what a romance it was. Here was this charming girl, whom the world only knew as a celebrated revue artiste, helping him to frustrate the criminal plans of her German father.

Ella, standing at the door, whispered:

“Hush!”

And without a word Seymour Kennedy, treading tiptoe, slipped within.

The house was familiar to him. He grasped the soft white hand of his well-beloved and, raising it to his lips, kissed it in homage. She was wearing a dainty purple and yellow kimono, her little feet thrust into red morocco Turkish slippers, which were noiseless, and, as she ascended the thickly-carpeted stairs, he followed her without uttering a word.

Up they went, to the top floor. The door which faced them at the head of the stairs she unlocked with a key, and after they were both inside she closed the door and then switched on the light.

The big chemical laboratory, which her father had established in secret in that long attic, presented the same scene as it had when he had visited it before at the invitation of his well-beloved. With such constant demands upon his inventive powers, it was necessary that the Prussian ex-professor should have the place fitted up with all the latest scientific appliances.

“Well, Seymour!” the girl exclaimed at last. “Here you are! What do you think of these?” And, crossing to a side table, she indicated two well-worn attaché-cases in brown leather, each about sixteen inches by eight, and three inches deep.

One of them she opened, revealing a curious mechanism within, part of which was the movement of a cheap American clock. Her tall, good-looking companion, who was a skilled mechanic, examined both these innocent-looking little cases with keen interest, and then exclaimed:

“Ah! I quite understand now! These are no doubt to be used in conjunction with explosives. They run for half an hour only, and then electrical contact is made into the explosive compound.”

“Exactly. See there, that row of tins of lubricating-oil. They are already filled with the high-explosive and in readiness.”

Kennedy bent and then saw, ranged below a bench on the opposite side of the laboratory, six tins of a certain well-known thick lubricating-oil used by motorists.

“There is sufficient there, dear, to blow up the whole of Barnes,” she declared. “Evidently this latest outrage is intended to be a serious one.”

“Ah!” sighed Kennedy. “It is a thousand pities, Ella, that your father is doing all this dastardly secret work for the enemy. Happily you, though his daughter, are taking measures to thwart his plans.”

“I am doing only what is my duty, dear,” replied the girl in the kimono; “and with your aid I hope to upset this latest plot of Ortmann and his friends.”

“Have you seen Ortmann lately?” her lover asked.

“No. He has been away somewhere in Holland—conferring with the German Secret Service, without a doubt. I heard father say yesterday, however, that he had returned to Park Lane.”

“Returned, in order to distribute more German money, I suppose?”

“Probably. He must have spent many hundreds of thousands of pounds in the German cause both before the war and after it,” replied the girl.

The pair stood in the laboratory for some time examining some of the apparatus which old Drost, now sleeping below, had during that day been using for the manufacture of the explosive contained in those innocent-looking oil-cans.

Kennedy realised, by the delicacy of the apparatus, how well versed the grey-haired old Prussian was in explosives, and on again examining the attaché-cases with their mechanical contents, saw the cleverness with which the plot, whatever its object, had been conceived.

What was intended? There was no doubt a conspiracy afoot to destroy some public building, or perhaps an important bridge or railway junction.

This he pointed out to Ella, who, in reply, said:

“Yes. I shall remain here and watch. I shall close up my flat, and send my maid on a holiday, so as to have excuse to remain here at home.”

“Right-ho! darling. You can always get at me on the telephone. You remain here and watch at this end, while I will keep an eye on Ortmann—at least, as far as my flying duties will allow me.”

Thus it was arranged, and the pair, treading noiselessly, closed the door and, relocking it, crept softly down the stairs. In the dark hall Seymour took his well-beloved in his strong arms and there held her, kissing her passionately upon the brow. Then he whispered:

“Good-night, my darling. Be careful that you are not detected watching.”

A moment later he had slipped out of the door and was gone.

Hardly had the door closed when Ella was startled by a movement on the landing at the head of the stairs—a sound like a footstep. There was a loose board there, and it had creaked! Some one was moving.

“Who’s there?” she asked in apprehension.

There was no reply.

“Some one is up there,” she cried. “Who is it?”

Yet again there was no response.

In the house there was the old servant and her father. Much puzzled at the noise, which she had heard quite distinctly, she crept back up the dark stairs and, finding no one, softly entered her father’s room, to discover him asleep and breathing heavily. Then she ascended to the servant’s room, but old Mrs Pennington was asleep.

When she regained her own cosy room, which was, as always, in readiness for her, even though she now usually lived in the flat in Stamfordham Mansions, over in Kensington, she stood before the long mirror and realised how pale she was.

That movement in the darkness had unnerved her. Some person had most certainly trodden upon that loose board, which she and her lover had been so careful to avoid.

“I wonder!” she whispered to herself. “Can there have been somebody watching us?”

If that were so, then her father and the chief of spies, the man Ortmann, would be on their guard. So, in order to satisfy herself, she took her electric torch and made a complete examination of the house, until she came to the small back sitting-room on the ground floor. There she found the blind drawn up and the window open.

The discovery startled her. The person, whoever it could have been, must have slipped past her in the darkness and, descending the stairs, escaped by the way that entrance had been gained.

Was it a burglar? Was it some one desirous of knowing the secrets of that upstairs laboratory? Or was it some person set to watch her movements?

She switched on the electric light, which revealed that the room was a small one, with well-filled bookshelves and a roll-top writing-table set against the open window.

Upon the carpet something glistened, and, stooping, she picked it up. It was a woman’s curb chain-bracelet, the thin safety-chain of which was broken.

Could the intruder have been a woman? Had the bracelet fallen from her wrist in her hurried flight? Or had it fallen from the pocket of a burglar who had secured it with some booty from a house in the vicinity?

Ella looked out into the small garden, but the intruder had vanished. Therefore she closed the window, to find that the catch had been broken by the mysterious visitor, and then returned again to her room, where she once more examined the bracelet beneath the light.

“It may give us some clue,” she remarked to herself. “Yet it is of very ordinary pattern, and bears no mark of identification.”

Next day, without telling her father of her midnight discovery, she met Seymour Kennedy by appointment at the theatre, showed him what she had found, and related the whole story.

“Strange!” he exclaimed. “Extraordinary! It must have been a burglar!”

“Or a woman?”

“But why should a woman break into your house?”

“In order to watch me. Perhaps Ortmann or my father may have suspicions,” replied the actress, arranging her hair before the big mirror.

“I hope not, Ella. They are both the most daring and the most unscrupulous men in London.”

“And it is for us to outwit them in secret, dear,” she replied, turning to him with a smile of sweet affection.

In the days that followed, the mystery of the intruder became further increased by Ella making another discovery. In the garden, upon a thorn-bush against the wall, Mrs Pennington found a large piece of cream silk which had apparently formed part of the sleeve of a woman’s blouse. She brought it to Ella, saying:

“I’ve found this in the garden, miss. It looks as if some lady got entangled in the bush, and left part of ’er blouse behind—don’t it? I wonder who’s been in our garden?”

Ella took it and, expressing little surprise, suggested that it might have been blown into the bush by the wind.

It, however, at once confirmed her suspicion that the midnight visitor had been a woman.

While Ella sang and danced nightly at the theatre, and afterwards drove home to Castelnau, to that house where upstairs was stored all that high-explosive, Seymour Kennedy maintained a watchful vigilance upon Ernst von Ortmann, the chief of enemy spies, and kept that unceasing watch over him, not only at the house at Wandsworth, but also at the magnificent mansion in Park Lane.

To von Ortmann’s frequent dinner-parties in the West End came the crafty and grave-faced old Drost, who there met other men of mysterious antecedents, adventurers who posed as Swiss, American, or Dutch, for that house was the headquarters of enemy activity in Great Britain, and from it extended many extraordinary and unexpected ramifications.

That some great and desperate outrage was intended in the near future Kennedy was confident, as all the apparatus was ready. But of Drost’s intentions he could discover nothing, neither could Ella.

One cold night, while loitering in the darkness beside the railings of the Park, Kennedy saw Ortmann emerge from the big portico of his house and walk to Hyde Park Corner, where he hailed a taxi and drove down Grosvenor Gardens. Within a few moments Kennedy was in another taxi closely following.

They crossed Westminster Bridge and turned to the right, in the direction of Vauxhall. Then, on arriving at Clapham Junction station, Kennedy, discerning Ortmann’s destination to be the house in Park Road, Wandsworth Common, where at times he lived as the humble Mr Horton, the retired tradesman, he dismissed his taxi and walked the remainder of the distance.

When he arrived before the house, he saw a light in Horton’s room, and hardly had he halted opposite ere the figure of a man in a black overcoat and soft felt hat came along and ascended the steps to the door.

It was the so-called Dutch pastor, Theodore Drost.

The latter had not been admitted more than five minutes when another visitor, a short, thick-set bearded man, having the appearance of a workman, probably an engineer, passed by, hesitated, looked at the house inquiringly, and then went up the steps and rang the bell.

He also quickly gained admission, and therefore it seemed plain that a conference was being held there that night.

The bearded man was a complete stranger, hence Kennedy resolved to follow him when he reappeared, and try to establish his identity. Being known to Drost and Ortmann, it was always both difficult and dangerous for him to follow either too closely. But with a stranger it was different.

Before twenty-four hours had passed, the Flight-Commander had ascertained a number of interesting facts. The bearded man was known as Arthur Cole, and was an electrician employed at one of the County Council power-stations. He lived in Tenison Street, close to Waterloo Station, and was a widower.

Next day, on making further inquiry of shops in the vicinity, a woman who kept a newspaper-shop exclaimed:

“I may be mistaken, sir, but I don’t believe much in that there Mr Cole.”

“Why?” asked Kennedy quickly.

“Well, ’e’s lived ’ere some years, you know, and before the war I used to order for ’im a German newspaper—the Berliner-Something.”

“The Berliner-Tageblatt it was, I expect.”

“Yes. That’s the paper, sir,” said the woman. “’E used to be very fond of it, till I couldn’t get it any more.”

“Then he may be German?”

The woman bent over the narrow counter of her small establishment and whispered:

“I’m quite certain ’e is, sir.”

That night Seymour saw his well-beloved in the theatre between the acts, and told her the result of his inquiries. Then he returned to his vigil and watched the dingy house in Tenison Street, one of those drab London streets in which the sun never seems to shine.

For three nights Kennedy remained upon constant vigil. On the fourth night, just as Ella was throwing off her stage dress at the conclusion of the show, she received a telegram which said: “Gone north. Return soon. Wait.”

It was unsigned, but she knew its sender.

Four days she waited in eager expectation of receiving news. On the fifth night, just before she left for the theatre, Ortmann arrived to visit her father. She greeted him merrily, but quickly escaped from that detestable atmosphere of conspiracy, at the same time remembering that mysterious female intruder.

Who could she have been?

In the meantime Seymour Kennedy, who had obtained a few days’ leave, had been living at the Central Hotel in that busy Lancashire town which must here be known as G—. To that town he had followed the man Cole and had constantly watched his movements. Cole had taken up his quarters at a modest temperance hotel quite close to the Central, which was the big railway terminus, and had been daily active, and had made several journeys to places in the immediate manufacturing outskirts of G—.

At last he packed his modest Gladstone bag and returned to London, Kennedy, in an old tweed suit, travelling by the same train.

On their arrival Kennedy took a taxi direct from Euston to the theatre.

When Ella had sent her dresser out of the room upon an errand, he hurriedly related what had occurred.

The man Cole had, he explained, met in G— a thin-faced, dark-haired young woman, apparently of his own social standing, a young woman of the working-class, who wore a brass war-badge in the shape of a triangle. The pair had been in each other’s company constantly, and had been twice out to a manufacturing centre about six miles away, a place known as Rivertown.

Briefly he related what he had observed and what he had discovered. Then he went out while she dressed, eventually driving with her to a snug little restaurant off Oxford Street, where they supped together.

“Do you know, Ella,” he asked in a low voice, as they sat in a corner, “now that we’ve established the fact that the man Cole has visited your father, and also that he is undoubtedly implicated in the forthcoming plot, can it be that this young woman whom he met in G— is the same who entered your father’s house on the night of my visit there?”

“I wonder!” she exclaimed. “Why should she go there?”

“Out of curiosity, perhaps. Who knows? She’s evidently on friendly terms with this electrician. Cole, who, if my information is correct, is no Englishman at all—but a German!”

Ella reflected deeply. Then she answered:

“Perhaps both the man and woman came there for the purpose either of robbery—or—”

“No. They were probably suspicious of your father’s manner, and came to examine the house.”

“But if they did not trust my father surely they would not be in active association with him, as you say they are,” the girl argued.

“True. But they might, nevertheless, have had their curiosity aroused.”

“And by so doing they may have seen us,” she declared apprehensively. “I hope not.”

“And even if they did, they surely would not recognise us again,” he exclaimed. “But,” he added, “no time must be lost. You must take another brief holiday from the theatre, and see what we can do.”

“Very well,” was the dancer’s reply. “I’ll see Mr Pettigrew to-morrow, and get a rest. It will give my understudy a chance.”

Over a fortnight went by.

It was half-past five o’clock on a cold January evening when a trainful of merry-faced girl munition workers stood at the Central Station at G— ready to start out to Rivertown to work on the night shift in those huge roaring factories where the big shells were being made.

Each girl wore a serviceable raincoat and close-fitting little hat, each carried a small leather attaché-case with her comb, mirror, and other little feminine toilet requisites, and each wore upon her blouse the brass triangle which denoted that she was a worker on munitions.

Peering out from the window of one of those dingy third-class compartments was a young girl in a rather faded felt hat and a cheap navy-blue coat, while upon the platform, apparently taking notice of nobody, stood a tallish young man in a brown overcoat. The munition-girl was Ella Drost, and the man her lover, Seymour Kennedy.

As the train at last moved out across the long bridge over the river, the pair exchanged glances, and then Ella, with her brass triangle on her blouse, sat back in the crowded carriage in thought, her little attaché-case upon her knees, listening to the merry chat of her fellow-workers.

Arrived at the station, she followed the crowd of workers to the huge newly-erected factory close by, a great hive of industry where, through night and day, Sunday and weekday, over eight thousand women made big shells for the guns at the front.

At the entrance-gate each girl passed singly beneath the keen eyes of door-keepers and detectives, for no intruder was allowed within, it being as difficult for strangers to gain admission there as to enter the presence of the Prime Minister at Downing Street.

The shifts were changing, and the day-workers were going off. Hence there was considerable bustle, and many of those lathes drilling and turning the great steel projectiles were, for the moment, still.

Presently the night-workers began to troop in, each in her pale-brown overall with a Dutch cap, around the edge of which was either a red or blue band denoting the status of the worker, while the forewomen were distinctive in their dark-blue overalls.

Some of the girls had exchanged their skirts for brown linen trousers. Those were the girls working the travelling cranes which, moving up and down the whole length of the factory, carried the shells from one lathe to another as they passed through the many processes between drilling and varnishing. Ella was among these latter, and certainly nobody who met her in her Dutch cap with its blue band, her linen overall jacket with its waistband, and her trousers, stained in places with oil, would have ever recognised her as the star of London revue.

Lithely she mounted the straight steep iron ladder up to her lofty perch on the crane, and, seating herself, she touched the switch and began to move along the elevated rails over the heads of the busy workers below.

The transfer of a shell from one lathe to another was accomplished with marvellous ease and swiftness. A girl below her lifted her hand as signal, whereupon Ella advanced over her, and let down a huge pair of steel grips which the lathe-worker placed upon the shell, at the same time releasing it from the lathe. Again she raised her hand, and the shell was lifted a few yards above her head and lowered to the next machine, where the worker there placed it in position, and then released it to undergo its next phase of manufacture.

Such was Ella’s work. In the fortnight she had been there she had become quite expert in the transfer of the huge shells, and, further, she had become much interested in her new life and its unusual surroundings In that great place the motive force of all was electricity. All those whirring lathes, drills, hammers, saws, cutting and polishing machines, cranes, everything in that factory, as well as the two other great factories in the near vicinity, were driven from the great electrical power-station close by.

Now and then, as the night hours passed, though within all was bright and busy as day, Ella would give a glance at the woman working the crane opposite hers, a thin-faced, dark-haired young woman, who was none other than the mysterious friend of the man Cole, and whom she held in great suspicion.

While Ella worked within the factory in order to keep a watchful eye, Seymour Kennedy watched with equal shrewdness outside.

The days went past, but nothing suspicious occurred until one night Cole, who was again living at the temperance hotel, joined the munition-workers’ train, being followed by Ella, who found that he had been engaged as an electrician in the power-house.

Next day he met the thin-faced young woman, who was known to her fellow-workers as Kate Dexter, and they spent several hours together, at lunch and afterwards at a picture-house. But, friends as they were, when they left the Central Station they took care never to travel in the same carriage. So, to their fellow-workers, they were strangers.

One afternoon, at half-past two, Kennedy, who was at the Central Hotel, called at Ella’s lodgings and explained how he had seen her father walking in the street with Cole.

“I afterwards followed them,” he added, “and eventually found that your father is at the Grand Hotel.”

“Then mischief is certainly intended,” declared the girl, her cheeks turning pale.

“No doubt. They mean to execute the plot without any further delay. That’s my opinion. It will require all our watchfulness and resource if we are to be successful.”

“Why not warn the police?” suggested the girl.

“And, by doing so, you would most certainly send your father to a long term of penal servitude,” was her lover’s reply. “No. We must prevent it, and for your own sake allow your father a loophole for escape, though he certainly deserves none.”

Ella had once travelled in the same train as the woman Dexter, but the latter had not recognised her; nevertheless, from inquiries Kennedy had made in London, it seemed that a month before the woman had been living in London, and was a close friend of Cole’s. She had only recently gone north to work on munitions, and had, like Ella, been instructed in the working of the electrical cranes.

For three days Theodore Drost remained at the Grand Hotel, where he had several interviews with the electrician Cole, and while Ella kept out of the way by day and went to the works at night, her lover very cleverly managed to maintain a strict watch.

More than once Ella had contrived to pass the door of the great power-station with its humming dynamos which gave movement to that huge mass of machinery in the three factories turning out munitions, and had seen the man Cole in his blue dungarees busily oiling the machinery.

Once she had watched him using thick machine-oil from cans exactly similar to those she had seen stored beneath the table in her father’s laboratory.

Night after night Ella, working there aloft in her crane, waited and wondered. Indeed, she never knew from hour to hour whether the carefully laid plans of the conspirators might not result in some disastrous explosion, in which she herself might be a victim.

But Kennedy reassured her that he was keeping an ever-watchful vigil, and she trusted him implicitly. As a matter of fact, one of the London detectives watching the place was a friend of his, and, without telling him the exact object of his visit, he was able to gain entrance to the works.

Naturally the detective became curious, but Kennedy, who usually wore an old tweed suit and a seedy cap, promised to reveal all to him afterwards.

About half-past one, on a wet morning, Ella had just stopped her crane when, at the entrance end of the building, she caught a glimpse of some one beckoning to her. It was her well-beloved. In a few moments she had clambered down, and, hurrying through the factory, joined him outside.

“Did you travel with that woman Dexter to-night?” he inquired eagerly in a low whisper as they stood in the darkness.

“Yes.”

“Did she carry her attaché-case?”

“Yes. She always does.”

“She did not have it when she went home yesterday morning, for she left it here—the case which your father prepared,” he said. “She brought the second of the cases with her to-night.”

“Then both are here!” exclaimed Ella in excitement.

“Both are now in the power-house. I saw her hand over the second one to Cole only a quarter of an hour ago. Let us watch.”

Then the pair crept on beneath the dark shadows through the rain to the great square building of red-brick which, constructed six months before, contained some of the finest and most up-to-date electrical plant in all the world.

At last they gained the door, which stood slightly ajar. The other mechanics were all away in the canteen having their early morning meal, and the man Cole, outwardly an honest-looking workman, remained there in charge.

Together they watched the man’s movements.

Presently he came to the door, opened it, and looked eagerly out. In the meantime, however, Kennedy and his companion had slipped round the corner, and were therefore out of view. Then, returning within, Cole went to a cupboard, and as they watched from their previous point of vantage they saw him unlock it, displaying the two little leather attaché-cases within.

Close to the huge main dynamo in the centre of the building there stood on the concrete floor six cans of lubricating-oil which, it was proved afterwards, were usually kept at that spot, and therefore were in no way conspicuous.

Swiftly the man Cole drew a coil of fine wire from the cupboard, the ends being joined to the two attaché-cases—so that if the mechanism of one failed, the other would act—and with quick, nimble fingers he joined the wire to that already attached to the six inoffensive-looking cans of “oil.”

The preparations did not occupy more than a minute. Then, seizing a can of petrol, he placed it beside the cans of high-explosive, in order to add fire to the explosion.

Afterwards, with a final look at the wires, and putting his head into the cupboard, where he listened to make certain that the clockwork mechanism was in motion, he glanced at the big clock above. Then, in fear lest he should be caught there, he ran wildly out into the darkness ere they were aware of his intention.

“Quick!” shouted Kennedy. “Rush and break those wires, Ella! I’ll watch him!”

Without a second’s hesitation, the girl dashed into the power-house and frantically tore the wires from the cupboard and from the fastenings to the deadly attaché-cases, and—as it was afterwards proved—only just in time to save herself, the building, and its mass of machinery from total destruction.

Meanwhile, Kennedy had overtaken the man Cole, and closed desperately with him, both of them rolling into the mud.

Just as Ella was running towards them a pistol-shot rang out.

The fellow had drawn a revolver and in desperation had tried to shoot his captor, but instead, in Kennedy’s strong grip, his hand was turned towards himself, and the bullet had struck his own face, entering his brain.

In a few seconds the man Cole lay there dead.

Was it any wonder that the Press made no mention of the affair?

Chapter Six.

The Silent Death.

In the yellow sunshine of a bright and cloudless autumn afternoon, Ella Drost descended from her motor-cycle at a remote spot where four roads crossed at a place called Pittsgate, about a mile and a half out from Goudhurst, in Kent, having travelled from London by way of Tunbridge Wells.

In leather cap, leggings, mackintosh, and leather belt she presented a charming type of the healthy English sports-girl. Indeed, in that very garb one could buy picture postcards of her all over the kingdom, those who purchased them little dreaming that Stella Steele, who had for so many nights been applauded by the khaki crowds in the theatre, where she merrily danced in the revue “Half a Moment!” was the daughter of old Theodore Drost, the sworn enemy of Great Britain, the man who had for so long succeeded in misleading the alien authorities into the belief that he was a pious pastor of the Dutch Church.

Certainly the man who posed as an ex-missionary from Sumatra, and who wore the shabby, broad-brimmed clerical hat and horn-rimmed glasses, had never once been suspected of treasonable acts, save by his daughter Ella and Seymour Kennedy.

It was to meet Kennedy that Ella had motored down from London that day. The roads were rather bad, and both machine and rider were splashed with mud. Yet for that she cared nothing. Her mind was too full of the investigations upon which they were engaged.

She took out a large scale map, unfolded it, and studied it carefully, apparently tracing a route with her finger. Then glancing at her wristlet-watch, she looked eagerly down the long, straight road upon her left—the road which led up from Eastbourne, through Mayfield and Wadhurst.

Nobody was in sight, therefore she consoled herself with a cigarette which she took from her case, and again studied her map until, at last, she suddenly heard the pop-pop-pop of a motor-cycle approaching and saw Seymour, his body bent over the handles, coming up the hill at a rattling pace.

In a few minutes he had pulled up, and, taking her in his arms, kissed her fondly, expressing regret if he were late.

“Eastbourne is further off than I expected, darling,” he added. “Well?” he asked eagerly.

“Nothing particular has happened since we parted on Thursday,” replied the girl. “Father has been several times to see Mr Horton in Wandsworth, and last night dined with Mr Harberton in Park Lane.”

“Ah! What would the public think if they knew that Count Ernst von Ortmann, who pulls the fingers of the Hidden Hand in our midst, Henry Harberton of Park Lane, and Mr Horton of Wandsworth, were one and the same person, eh?” exclaimed the man, who, though not in uniform, revealed his profession by his bearing.

“One day it will be known, dear,” said the girl. “And then there will be an end to my father. The Count will believe that my father has betrayed him.”

“Why do you anticipate that?”

“Because only the night before last, when Ortmann called, I overheard him remark to my father that he was the only person who knew his secret, and warning him against any indiscretion, and of the fate which Germany would most certainly meet out to him if any contretemps occurred.”

“Yes,” remarked the air-pilot reflectively. “I suppose that if the authorities really did arrest the inoffensive and popular Mr Harberton, the latter would, no doubt, revenge himself most bitterly upon your father.”

“Of that I’m perfectly certain, dear. Often I am tempted to relinquish my efforts to combat the evil they try to work against England, and yet the English are my own people—and also yours.”

“You’re a thorough brick, Ella. There’s not a girl in all the kingdom who has run greater risks than your dear self, or been more devoted to the British cause. Why, a dozen times you’ve walked fearlessly into danger, when you might have been blown to atoms by their infernal bombs.”

“No, no,” she laughed. “Don’t discuss it here. I’ve only done what any other girl in my place would have done. Come,” she added. “Let’s get on and carry out the plan we arranged.”

“Right-ho!” he replied. “That’s the road,” he added, pointing straight before him. “According to the map, there’s a wood a little way up, where the road forks. We take the left road, skirt another wood past a farm called Danemore, then over a brook, and it’s the first house we come to on the right—with another wood close behind it.”

“Very well,” answered the girl. “You’ll have a breakdown close to the house—eh?”

“That’s the arrangement,” he laughed, and next minute he was running beside his machine, and was soon away, followed by his mud-bespattered well-beloved.

Off they both sped, first down a steep slope, and then gradually mounting through a thick wood where the brown leaves were floating down upon the chilly wind. They passed the farm Kennedy had indicated, crossed the brook by a bumpy, moss-grown bridge, and suddenly the man threw up his hand as a signal that he was pulling-up, and, slowing down, alighted, while his engine gave forth a report like a pistol-shot.

Ella, too, dismounted, and saw they were before a good-sized, well-kept farmhouse, which stood a short distance back from the road, surrounded by long red-brick outbuildings.

The report had brought out an old farm-hand—a white-bearded old fellow, who was scanning them inquisitively.

Both Ella and her lover were engaged in intently examining the latter’s machine, looking very grave, and exchanging exclamations of despair. Kennedy opened a bag of tools and, with a cigarette in his mouth, commenced an imaginary repair, with one eye upon the adjacent house. This lasted for about a quarter-of-an-hour. In the meantime a woman, evidently the farmer’s wife, had come out to view the strangers, and had returned indoors.

“I think it’s now about time we might go in,” the air-pilot whispered to his companion, whereupon both of them entered the gate and passed up the rutty drive to the house.

“I wonder if you could lend me a heavy hammer?” asked the motor-cyclist in distress of the pleasant, middle-aged woman who opened the door.

“Why, certainly, sir. Would the coal-hammer do?” she asked.

“Fine!” was the man’s reply. “I’m so sorry to trouble you, but I’ve broken down, and I’m on my way to London.”

“I’m very sorry, sir,” exclaimed the woman, who fetched a heavy hammer from her kitchen. “Would the young lady care to come in and wait?”

“Oh, thanks. It’s awfully good of you,” said Ella. “The fact is I am a little fagged, and if I may sit down I shall be so grateful.”

“Certainly, miss. Just come in both of you for a moment,” and she led the way into a homely well-furnished room with a great open hearth where big logs were burning with a pleasant smell of smouldering beech.

“What a comfortable room you have here!” Kennedy remarked, looking at the thick Turkey carpet upon the floor, and the carved writing-table in the window.

“Yes, sir. This is a model dairy-farm. It belongs to Mr Anderson-James, who lives in Tunbridge Wells, and who comes here for week-ends sometimes, and for the shooting. I expect him here to-night. My husband farms for him, and I look after the place as housekeeper.”

“A model farm!” exclaimed Ella. “Oh! I’d so much like to see it. I wonder if your husband would allow me?”

“He’d be most delighted, miss.”

“Stevenson is my name, and this is my friend Mr Kershaw,” Ella said, introducing herself.

“My name is Dennis,” replied the comely farmer’s wife with a pleasant smile. “This is called Furze Down Farm, and Mr Anderson-James is a solicitor in Tunbridge Wells. So now you know all about us,” and the woman, in her big white apron, laughed merrily.

Kennedy and the girl exchanged glances.

“Well,” he said, “I’ll go out and try to put the machine right. It won’t take very long, I hope. If I can’t—well, we must go back by train. Where’s the nearest station, Mrs Dennis?”

“Well—Paddock Wood is about two miles,” was her reply. “If you can’t get your motor right my husband will put it into a cart and drive you over there. It’s the direct line to London.”

“Thanks so much,” he said, and went out, leaving Ella to rest in the cosy, well-furnished room which the solicitor from Tunbridge Wells occupied occasionally through the week-ends.

“Mr Anderson-James keeps this place as a hobby. He’s retired from practice,” the woman went on, “and he likes to come here for fresh air. When you’ve rested I’ll show you round the houses—if you’re interested in a dairy-farm.”

“I’m most interested,” declared the girl. “I don’t want to rest. I’d rather see the farm, if it is quite convenient to you to show it to me.”

“Oh, quite, miss,” was the woman’s prompt response. She came from Devonshire, as Ella had quickly detected, and was an artist in butter-making, the use of the mechanical-separator, and the management of poultry.

The pair went out at once and, passing by clean asphalt paths, went to the range of model cowhouses, each scrupulously clean and well-kept. Then to the piggeries, the great poultry farm away in the meadows, and, lastly, into the white-tiled dairy itself, where four maids in white smocks and caps were busy with butter, milk, and cream.

Ranged along one side of the great dairy were about thirty galvanised-iron chums of milk, ready for transport, and Ella, noting them, asked their destination.

“Oh! They go each night to the training-camp at B—. They go out in two lots, one at midnight, and one at two o’clock in the morning.”

“Oh, so you supply the camp with milk, do you?”

“Yes. Before the war all our milk went up to London Bridge by train each night, but now we supply the two camps. There are fifty thousand men in training there, they say. Isn’t it splendid!” added the woman, the fire of patriotism in her eyes. “There’s no lack of pluck in the dear old country.”

“No, Mrs Dennis. All of us are trying to do our bit,” Ella said. “Does the Army Service Corps fetch the milk?”

“No, miss. They used to, but for nearly six weeks we’ve sent it in waggons ourselves. The camp at B— is ten miles from here, so it comes rather hard on the horses. It used to go in motor-lorries. Old Thomas, the man bending down over there,” and she pointed across the farm-yard, “he drives the waggon out at twelve, and Jim Jennings—who only comes of an evening—does the late delivery.”

“But the road is rather difficult from here to the camp, isn’t it?” asked the girl, as though endeavouring to recollect.

“Yes. That’s just it. They have to go right round by Shipborne to avoid the steep hill.”

Five minutes later they were in the comfortable farm-house again, and, after a further chat, Ella went forth to see how her companion was progressing.

The repair had been concluded—thanks to the coal-hammer! Ella took it back, thanked the affable Mrs Dennis, and, five minutes later, the pair were on their way to London, perfectly satisfied with the result of their investigations.

On that same evening, while Kennedy and Ella were having a light dinner together at the Piccadilly Grill before she went to the theatre, the elusive Ortmann called upon old Theodore Drost at the dark house at Castelnau, on the Surrey side of Hammersmith Bridge. He came in a taxi, and accompanying him was a grey-haired, tall, and rather lean man, who carried a heavy deal box with leather handle.

Drost welcomed them, and all three ascended at once to that long attic, the secret workshop of the maker of bombs. The man who posed as a pious Dutch missionary switched on the light, disclosing upon the table a number of small globes of thin glass which, at first, looked like electric light bulbs. They, however, had no metal base, the glass being narrowed at the end into a small open tube. Thus the air had not been exhausted.

“This is our friend, Doctor Meins,” exclaimed Ortmann, introducing his companion, who, a few minutes later, unlocked the box and brought out a large brass microscope of the latest pattern, which he screwed together and set up at the further end of the table.

Meanwhile from another table at the end of the long apartment old Drost, with a smile of satisfaction upon his face, carried over very carefully a wooden stand in which stood a number of small sealed glass tubes, most of which contained what looked like colourless gelatine.

“We want to be quite certain that the cultures are sufficiently virulent,” remarked Ortmann. “That is why I have brought Professor Meins, who, as you know, is one of our most prominent bacteriologists, though he is, of course, naturalised as a good Englishman, and is in general practice in Hampstead under an English name.”

The German professor, smiling, took up one of the hermetically sealed tubes, broke it, and from it quickly prepared a glass microscope-slide, not, however, before all three had put on rubber gloves and assumed what looked very much like gas-helmets, giving the three conspirators a most weird appearance. Then, while the Professor was engaged in focussing his microscope, Drost, his voice suddenly muffled behind the goggle-eyed mask, exhibited to Ortmann one of the glass bombs already prepared for use.

It was about the size of a fifty-candle-power electric bulb, and its tube having been closed by melting the glass, it appeared filled with a pale-yellow vapour.

“That dropped anywhere in a town would infect an enormous area,” Drost explained. “The glass is so thin that it would pulverise by the small and almost noiseless force with which it would explode.”

“It could be dropped by hand—eh?” asked Ortmann. “And nobody would be the wiser.”

“No, if dropped by hand it would, no doubt, infect the person who dropped it. The best way will be to drop it from a car.”

“At night?”

“No. In daylight—in a crowded street. It would then be more efficacious—death resulting within five days to everyone infected.”

“Terrible!” exclaimed the Kaiser’s secret agent—the man of treble personality.

“Yes. But it is according to instructions. See here!” and he took up what appeared to be a small bag of indiarubber—like a child’s air-ball that had been deflated. “This acts exactly the same when filled, only the case is soluble. One minute after touching water or, indeed, any liquid, it dissolves, and thus releases the germs!”

“ Gott !” gasped Ortmann. “You are, indeed, a dealer in bottled death, my dear Theodore. Truly, you’ve been inventing some appalling things for our dear friends here—eh?”

The man with the scraggy beard, who was a skilled German scientist, though he posed as a Dutch pastor, smiled evilly, while at that moment the man Meins, who had his eye upon the microscope, beckoned both of them forward to look.

Ortmann obeyed, and placing his eye upon the tiny lens, saw in the brightly reflected light colonies of the most deadly bacilli yet discovered by German science—the germs of a certain hitherto unknown disease, against which there was no known remedy. The fifth day after infection of the human system death inevitably resulted.

“All quite healthy!” declared the great bacteriologist from behind his mask. “What would our friends think if they knew the means by which they came into this country—eh?”

Drost laughed, and, crossing to a cupboard, took out a fine Ribston-pippin apple. This he cut through with his pen-knife, revealing inside, where the core had been removed, one of the tiny tubes secreted.

“They came like this from our friends in a certain neutral country,” he laughed.

From tube after tube Meins took and examined specimens, finding all the cultures virulent except one, which he placed aside.

Then, turning to Drost, he gave his opinion that their condition was excellent.

“But be careful—most scrupulously careful of yourself, and of whoever lives here with you—your family and servants. The bacteria are so easily carried in the air, now that we have opened the tubes.”

“Never fear,” replied the muffled voice of Ella’s father. “I shall be extremely careful. But what is your opinion regarding this?” he added, showing the professor one of the tiny bags of the soluble substance.

Meins examined it closely. Obtaining permission, he cut out a tiny piece with scissors and placed it beneath his powerful microscope.

Presently he pronounced it excellent.

“I see that it is impervious. If it is soluble, as you say, then you certainly need have no fear of failure,” he said, with a benign smile. Then he set to work to reseal the tubes he had opened, while Drost, with a kind of syringe, sprayed the room with some powerful germ-destroyer.

Ten minutes later the pair had descended the stairs, while old Drost had switched off the light and locked the door of the secret laboratory wherein reposed the germs of a terrible disease known only to the enemies of Great Britain—a fatal malady which Germany intended to sow broadcast over the length and breadth of our land.

For an hour they all three sat discussing the diabolical plot which would disseminate death over a great area of the United Kingdom, for Germany had many friends prepared to sacrifice their own lives for the Fatherland, and it was intended that those glass and rubber bombs should be dropped in all quarters to produce an epidemic of disease such as the world had never before experienced.

Old Theodore Drost, installed in his comfortable dining-room again, opened a long bottle of Berncastler “Doctor”—a genuine bottle, be it said, for few who have sipped the “Doctor” wine of late have taken the genuine wine, so many fabrications did Germany make for us before the war.

“But I warn you to be excessively careful,” the professor said to Drost. “Your daughter comes here sometimes, does she not? Do be careful of her. Place powerful disinfectants here—all over the house—in every room,” he urged; “although I have plugged the tubes with cotton wool properly treated to prevent the escape of the infection into the air, yet one never knows.”

“Ella is not often here,” her father replied. “She is still playing in ‘Half a Moment!’; besides, she is rehearsing a new revue. So she, happily, has no time to come and see me.”

“But, for your own safety, and your servant’s, do be careful,” Meins urged. “To tell you the honest truth, I almost fear to remove my mask—even now.”

“But there’s surely no danger down here?” asked Drost eagerly.

“There is always danger with such a terribly infectious malady. It is fifty times more fatal than double pneumonia. It attacks the lungs so rapidly that no remedy has any chance. Professor Steinwitz, of Stettin, discovered it.”

“And is there no remedy?”

“None whatsoever. Its course is rapid—a poisoning of the whole pulmonary system, and it’s even more contagious than small-pox.”

Then they removed their masks and drank to “The Day” in their German wine.

Six nights later Stella Steele had feigned illness—a strain while on her motor-cycle, and her understudy was taking her part in “Half a Moment!” much to the disappointment of the men in khaki, who had seated themselves in the stalls to applaud her. Among the men on leave many had had her portrait upon a postcard—together with a programme in three-colour print—in their dug-outs in Flanders, for Stella Steele was “the rage” in the Army, and among the subalterns any who had ever met her, or who had “known her people,” were at once objects of interest.

In the darkness on a road with trees on either side—the road which runs from Tonbridge to Shipborne, and passes between Deene Park and Frith Wood—stood Kennedy and Ella. They had ridden down from London earlier in the evening and placed their motorcycles inside a gate which led into the forest on the left side of the road.

They waited in silence, their ears strained, but neither uttered a word. Kennedy had showed his well-beloved the time. It was half-past one in the morning.

Of a sudden, a motor-car came up the hill, a closed car, which passed them swiftly, and then, about a quarter-of-a-mile further on, came to a halt. Presently they heard footsteps in the darkness and in their direction there walked three men. The moon was shining fitfully through the clouds, therefore they were just able to distinguish them. The trio were whispering, and two of them were carrying good-sized kit-bags.

They came to the gate where, inside, Ella and Kennedy had hidden their cycles, and there halted.

That they were smoking Kennedy and his companion knew by the slight odour of tobacco that reached them. For a full quarter-of-an-hour they remained there, chatting in low whispers.

“I wonder who they are?” asked Ella, bending to her lover’s ear.

“Who knows?” replied the air-pilot. “At any rate, we’ll have a good view from here. You were not mistaken as to the spot?”

“No. I heard it discussed last night,” was the girl’s reply.

Then, a moment later, there was a low sound of wheels and horses’ hoofs climbing the hill from the open common into that stretch of road darkened by the overhanging trees. Ella peered forth and saw a dim oil lamp approaching, while the jingling of the harness sounded plain as the horses strained at their traces.

Onward they came, until when close to the gate where the three men lay in waiting, one of the latter flashed a bright light into the face of the old man who was driving the waggon, and shouted:

“Stop! Stop !”

The driver pulled up in surprise, dazzled by the light, but the next second another man had flung into his face a mixture of cayenne pepper and chemicals by which, in an instant, he had become blinded and stupefied, falling back into his seat inert and helpless.

Then Ella and Kennedy, creeping up unnoticed by the three in their excitement, saw that they had mounted into the waggon, which was loaded with milk-churns—the waggon driven nightly from Furze Down Farm to the great camp at B—, carrying the milk for the morning.

Upon these chums the three set swiftly to work, opening each, dropping in one of those soluble bombs, and closing them. The bombs they took from the two kit-bags they had carried from the car.

They were engaged in carrying out one of the most dastardly plots ever conceived by Drost and his friends—infecting the milk supply of the great training-camp!

Kennedy was itching to get at them and prevent them, but he saw that, by knowledge gained, he would be in a position to act more effectively than if he suddenly alarmed them. Therefore the pair stood by until they had finished their hideous work of filling each chum with the most deadly and infectious malady known to medical science.

Presently, when they had finished, the old driver, still insensible, was lifted from his seat, carried into the wood, and there left, while one of the conspirators—who they could now see was dressed as a farm-hand, and would no doubt pose as a new labourer from Furze Down—took his place and drove on as though nothing had happened, leaving the other two to make their way back to the car.

When the red rear-light of the waggon was receding, Kennedy and Ella followed it, for it did not proceed at much more than walking pace.

They walked along in silence till they saw the two men re-enter the car, leaving their companion to deliver the milk at the camp. Evidently a fourth man had been waiting in the car for, as soon as they were in, the man who drove turned the car, which went back in the direction it had come, evidently intending to meet the second waggon, which was due to come up an hour afterwards. No doubt the same programme would be repeated, and the fourth man would drive the second car to the adjacent camp.

As soon, however, as the car had got clear away, Kennedy and his well-beloved ran to their motorcycles, mounted them, and in a short time had passed in front of the milk-waggon ere it could get down into Shipborne village.

Putting their motors against a fence, they waited until the waggon came up, when Kennedy stepped into the road, and flashing an electric lamp on to the driver’s face, at the same time fired a revolver point-blank at him.

This gave the fellow such a sudden and unexpected scare that he leaped down from the waggon and, next moment, had disappeared into the darkness, while Ella rushed to the horses’ heads and stopped them.

“That’s all right!” laughed Kennedy. “Have you got your thick gloves on?”

“Yes, dear.”

“Well, be careful that not a drop of milk goes over your hands or feet. There’s lots of time to pitch it all out on the roadway.”

Then climbing into the waggon the pair, by a pre-arranged plan, began to open the chums and turn their contents out of the waggon until the whole wet roadway was white with milk, which soaked into the ground and ran into the gutters and down the drains: for, fortunately, being near Shipborne, the footpaths on either side were drained, and by that any chance of infection later would, they knew, be minimised.

Each chum they turned upon its side until not a drain of milk remained within, and then, leading the horses to graze on the grass at the roadside, the pair sped swiftly back along the road in the direction the car had taken.

About five miles away they found the conspirators’ car upon the side of the road without any occupant. They were waiting for the second waggon.

Without ado, Kennedy mounted into it, started it, and drew it out into the middle of the road, which at that point was upon a steep gradient.

Then, taking a piece of blind-cord from his pocket, he swiftly tied up the steering-wheel and, jumping out, started the car down the hill.

Away it flew at furious speed, gathering impetus as it went. For a few moments they could hear it roaring along until, suddenly, there was a terrific crash.

“That’s upset their plans, I know,” he laughed to Ella.

“We’ll go and investigate in a moment, and watch the fun.”

This they did later on, finding the car turned turtle at the bottom of the hill, with three men standing around it in dismay.

Kennedy inquired what had happened, but neither would say much.

Yet, while they stood there, the second milk-laden waggon approached, passed, and went onward, its sleepy driver taking no notice of the five people at the roadside.

For half-an-hour Kennedy and Ella remained there in pretence of endeavouring to right the car, until they knew that the waggon, with its contents, was well out of harm’s way.

Then they remounted and returned to London, having, by their ingenious investigations and patient watching, saved the lives of thousands of Great Britain’s gallant boys in khaki.

Two days later Theodore Drost was taken suddenly ill with symptoms which puzzled his local doctor at Barnes. He spoke to Ortmann over the telephone, but the latter dared not risk a visit to Castelnau. Ella also heard from her father over the telephone when, that night, she returned to Stamfordham Mansions at the end of the “show.” She, knowing all she did, regarded a visit there as too dangerous, but rang up Kennedy at his air-station and guardedly informed him of the situation.

Five days later Theodore Drost lay dead of a malady to which the bespectacled doctor at Barnes gave a name upon his certificate, but of which he was really as ignorant as his own chauffeur.

But the curious part of the affair was that while Drost lay dead in the house, and the night before his burial, a mysterious fire broke out which gutted the place, a fact which no doubt must have been a great mystery to Ortmann and his friends.

The Metropolitan Fire Brigade still entertain very grave suspicions that it was due to an incendiary because of its fierceness; yet who, they ask themselves, could have had any evil design upon the property of the poor dead Dutch pastor?

The End.