We stood before the airlock, the old man and I, and watched them go out. Ellison was a granite man and I was just the lad who threw the switches.

I was new at it. They had sent me out with a pat on the back and a commission, but I didn't feel like a Mercury run officer. Mining uranium on the Sun's firstling was no job for a green kid of twenty-two. Outside were lakes of molten zinc and a temperature of 790 degrees Fahr.

No part of that temperature seeped into us, but just knowing it was out there was spine-chilling. I am not being facetious. To keep from thinking of the hot face we thought of the cold face, and you can't imagine extremes of cold without feeling shivery. Out on the cold face were other miners, working under conditions I wouldn't wish on my worst enemy. They had the cold of open space to contend with, and a little of that seeped in.

The Commander was passing out advice to each of the miners as they stepped into the lock.

"Murphy, it's uranium we want. We're not zoologists. The next time you go specimen chasing—"

"But it looked like a frog, Chief. I swear it did."

"You know damn well no froglike animal could hop around on red-hot rocks."

"I won't let him out of my sight this time, sir," said the miner at Murphy's heels.

"Thank you, Haines. He needs a nurse, but do what you can."

Five miners stepped out, each with a glance from Ellison which said as plain as words that he would walk beside them until they came back in again. The old man had so much quiet strength that he could split off simulacra of himself, and send them out through the airlock by just passing out advice. He moved like a living presence over the semi-molten Mercurian crust beside each of his men, fretting when a coupling slipped or mysterious stirrings caused the lads to look at one another with a wild surmise.

He knew that the merciless heat beating down did something to the scarred and cracked surface rocks which made them seem to buckle and split up into little leaping ghosts, and half his warnings were directed against "heat-devils" and other optical illusions.

When the last man had passed out he turned to me with a wry smile. "Dave, speaking as a psychiatrist, and without knowing for sure, I've a hunch there is too much tension inside of you."

The old man actually was a psychiatrist. You have to be pretty nearly everything to qualify as a Mercury run commander and Ellison's knowledge started with Aasen and ended with Zwolle. There were some gaps in between, but not many, and he frequently surprised me by pulling rabbits out of those.

We went down into the cuddy and the old man brought out some real smoky Scotch, and we had at least three while a strained look came into his face. One of these days someone is going to stop putting bulkhead chronometers in the cuddies of Mercury run spaceships. Men have to go out and Commanders have to wait, and if an officer can't get his mind off the seconds in a cuddy what chance has he of relaxing at all?

Hanging on the corrugated metal bulkhead were curios from all over the Solar System, and I tried to interest myself in the things the Commander had collected in his travels. A dried Venusian weejee head looks pretty grotesque, but so does a deep-sea fish from home, and when you've seen both dozens of times—

A sudden vibrant humming made me spill a jigger of Scotch on my liberty uniform. The lad who was taking my place at the lock control was buzzing the old man from the "peel off" room. Ellison swung about, and barked into the auxiliary circuit audiocoil. "Well?"

"The men have returned, sir."

"All right. Keep the inner locks closed and watch the insulators. Rawley is taking over."

Between the outer and inner locks we had to cool off the men a little. When they stepped in from the crust the sheath couplings on their non-combustible suits had to be sprayed over with liquid air.

We went up in the jacket-lift with our knees braced and down the stern passageway to the "peel off" room, the old man striding on ahead of me. Had I stopped to reflect I might have realized there was trouble brewing. The old man wasn't psychic exactly, but his hunches came out pat.

Before I looked through the lock port my nerves were merely jumpy, but when I actually saw Murphy standing in the freeze vault enveloped in smoke and sizzle I nearly passed out from shock.

Murphy was waving his arms up and down and the man behind him was making frantic signs to us. The frog was dangling by its long legs from the Irishman's gloved right hand. It was about three feet in height. Every time he raised it up it tried to leap in his hand, and twisted its eyes around.

Some quirk of parallel evolution had given it a froglike face, webbed feet and long, powerful hindlimbs. But, of course, it wasn't a frog. It was a Mercurian animal, and my stomach went tight ten seconds after I laid eyes on it.

I've said that I was just a green kid. The old man thought otherwise, but he was wrong and I proceeded to prove it. I turned on the freeze conduits. Liquid air poured into the vault over Murphy and he stopped gesticulating. He just stood there looking at me through the eye-piece of his helmet.

Murphy had gone out at the risk of his life and brought back a living Mercurian animal. When he perceived that I had frozen that frog to a crisp something must have gone dead inside him. When he came in through the inner locks his couplings were coated with frost and there was a look of anguish on the upper part of his face. Behind the eye-piece his features seemed all wrenched apart. From his gloved right hand the frog still dangled, but its squirmings had ceased. Its limbs were rigid, its stalked eyes frozen shut.

With shaking fingers Murphy removed his helmet and started peeling off his suit, his gaze riveted on my face. The other miners stood watching him as though fearful of what he might do.

The old man laid a hand on my arm. "You'd better go below, Dave."

Murphy shook his head. "No, no, let the lad stay."

He had laid the frog on the deck and was pushing his suit down below his knees. I noticed that his features were twitching, but I thought he was making an effort to control his anger until he came up out of that crouch with all his strength riding on his fists.

He clipped me on the side of the head, and delivered a blow to my midriff which sent me reeling back against the bulkhead.

The old man leapt between us. "Watch yourself, Murphy," he thundered. "I'm still in command here."

Murphy spat on the deck, a slow flush creeping up over his face. "I just can't figure it," he muttered. "I saw an infant once without one, but its skull tapered and it had to be fed through a tube."

I had always liked Murphy, but suddenly I saw red. I jumped him, and for a minute it was touch and go. We rolled over on the deck, exchanging hammer blows. He was hampered by the tangle his legs were in, but he made good use of his fists.

The old man had to intervene again. He accomplished it by backing up his tuggings with profanity. He cast aspersions on our ancestry, and threatened us with the psycho-lash.

I'm hot-tempered, but I cool off quickly. The instant I realized I was making it tough for the old man I struggled to my feet, and held out my hand.

"Any time you're ready, Murphy," I said.

The Irishman rose groggily, shaking his head to clear it. He stood for a minute staring incredulously at my extended palm, his eyebrows twitching. Then his own hand went out and locked with mine.

"I guess I was a bit hasty, lad," he said.

Ten minutes later Sylvia was placing cool pads on my face, one on each cheek, and shaking her head over my blackened eye. "I'm not really sorry for you, Dave," she said. "You apparently enjoy lashing out with your fists. You just used that frog as an excuse."

Perhaps I should have mentioned sooner that there was a woman on board. A slim and attractive girl with coppery hair named Sylvia Varner was visiting us for five days consecutively. But she had come out on the crew-shift cruiser Aquila which was berthed right alongside of us on the semi-molten crust.

Women are out of place on Mercury run ships, and if I were taking fictional liberties with this record I'd leave her out. But facts are facts, and the feminine zig-zag had a lot to do with the way the frog brought us all to the brink of despair. Without her it would have been less though, but less exciting, too, and, of course, for romantic reasons I was glad she had come. She happened to be Ellison's niece, and my fiancee, and had a kid brother working on the metallurgical staff.

"But it isn't a frog," I said, irritably. "It's a Mercurian animal. And I don't blame Murphy for sailing into me."

"You're being very charitable," she said. "He tried to kill you."

"All right," I said. "For a minute he went berserk. But what would you do if you bagged the first Mercurian animal ever seen and a dumb kid turned it into a museum piece? If Murphy could have brought that frog back to Earth alive the National Geographic Society would have smothered him with medals."

"But won't it thaw out, Dave?"

"It's limper than a rag right now," I said. "But it is also dead as a doornail."

Sylvia's brow crinkled. "I should think a Mercurian animal would have to be plated like an armadillo. I should think it would need some sort of air-cooling system and a—"

"Hold on," I said. "You're jumping to a priori conclusions. We'll start with the animal. It is froglike, so conditions on Mercury must favor the development of slender, agile quadrupeds with powerful hindlimbs. Since Mercury is flecked with semi-molten 'marsh patches' its froglike appearance does not surprise me. We can only speculate as to its habits, but it's probably oviparous, and has a brief life-cycle.

"Now, in hot baths with carefully regulated approaches human beings have been able to stand degrees of heat above the boiling point of water. Back in the eighteenth century a Frenchman named Chamouni the Incombustible entered an oven containing a raw leg of mutton, and remained there until the meat was completely cooked. Medical history records hundreds of similar cases."

"But what has that to do with Murphy's frog?"

"Don't you see? If human beings can build up all that resistance in a few minutes what's to stop a rapidly breeding Mercurian animal from acquiring ten times as much immunity in fifty thousand generations? With already immune invertebrates to start with natural selection could give even a highly evolved, meaty-fleshed animal plenty of resistance."

I was feeling distinctly proud of myself when Sylvia countered with: "You said the sides of its body and its hindlimbs were covered with fine, reddish hairs. Villosities was the term you used. How could natural selection build up immunity in hair?"

I could have brought up another player, but I wanted her to smooth my forehead instead. So I leaned back with a sigh and refrained from pointing out that chitin was slow-burning at best, and that the only hairy frog on Earth—Trichobatatrachus robustus from West Africa—lived up to its name.

She sat on the arm of my chair and leaned forward and for a minute I thought I was going to get my wish. But all she did was kiss me. She leaned her lips against mine and for about three minutes a pleasant tingling surged through me. Then I began to grow restless. I couldn't breathe and her lips were no longer warm and vibrant.

I had to move her face to one side in order to inhale, and the instant I did so she swayed and her elbows descended on my chest.

A chill coursed through me. Her arms were rigid and she seemed almost weightless. Alarmed, I rose, grasped her wrists and eased her gently down into the chair.

She just sat there staring up at me, her face a petrified mask and her body so utterly still that it did something to sound. In place of the faint susurrous which occupied space gives forth the chair seemed to be enveloped in a kind of auditory vacuum which chilled me to the core of my being.

I can't remember how long I stood there with horror slapping at my brain like the tides of some cold, dead moon. I only know that I turned at last and went stumbling from her presence with one thought uppermost in my mind.

I must get medical aid to her quickly, before that trance could deepen, before it could endanger her life.

Going up in the jacket-lift to the sick bay I kept visualizing Ned Dawson's face. Dawson was a strong-jawed, competent physician with years of experience behind him and I was sure he would know what to do.

He was usually in the sick bay attending to the many little sprains and bruises the men brought in with them from the crust. There was a flicker of violet light as the jacket-lift hummed to a stop. I stepped out and raced down a cold-lighted passageway to the "drug shop," my breath coming fast.

On meta-glass chairs amidst a faint odor of antiseptics two men sat frozen, but I thought they were asleep. I went straight through the waiting space with scarcely a glance at them, and burst into the sick bay unannounced.

Dawson was there all right, but he was bent nearly double, frozen in the act of applying a gauze bandage to the badly cut ankle of a miner who stood contemplating his navel like a schizophrene, his head sunken on his chest.

For an instant I just stood there gasping, too stunned to realize that I was staring at a physician who could no longer heal. It wasn't until I went up to him and discovered that his body was cold and his face a frozen mask that my brain started to soak up horror.

I went reeling out into the passageway like a drunken man and tried to locate the commander, and found him at last in the control room with his body glinting in light-silvered dust.

He was standing before one of the Lyra's translucent windows staring out upon the steamy Mercurian landscape, his arms folded on his chest. When I touched him he swayed and when I looked into his eyes I perceived that the pupils were set in a fixed stare, and covered with a dull, grayish film.

Murphy was standing beside him. The Irishman had evidently come in for orders and stiffened to immobility with a pipe in his mouth and a slightly provoked look on his face, as though my stupidity still riled him.

A nightmare unreality lengthened the minutes which followed into unevenly-spaced eternities filled with a steadily mounting dread. In the more crowded parts of the ship frozen men clustered in little queues. Every member of the atomotor crew stood frozen at his post. The starboard watch looked like statues carved in bronze and in the chain locker room were three crewmen whose muscular contortions conveyed an illusion of motion as they tugged at windlasses which had ceased to turn.

My palms were wet and I was trembling in every limb when I completed my inspection of the ship. It was especially bad going back in the jacket-lift to the commander's cabin. In the dark fore-hold I had glimpsed obscure, rigid shadows which had unnerved me more than all the frozen, brittle men illumed by cold light in the crew spaces fore and aft.

When I stepped from the jacket-lift a voice said: "They only seem brittle, Rawley. Actually they are still soft and flabby, like all the inhabitants of the third planet."

It was a telepathic voice, but I didn't know that. I thought it was a human voice speaking close to my ear. Appalled, I swung about.

The frog was peering around a bend in the passageway, its stalked eyes pointing toward the lift. I fought a desire to scream as it leapt agilely toward me. It seemed to be grinning up at me. Its wet, yellowish lips were split in a grimace which gave it the appearance of being convulsed with mirth.

"Why are you trembling, Rawley?" it said. "Surely you expected to find intelligent life on at least one of the planets."

"You mean you are—"

"Intelligent, yes. So intelligent that you seem very primitive to us. It is a hindrance, in a way. Too wide a gulf."

"Then you did this," I choked. "You—you froze every man on this ship."

"Froze? Oh, I see what you mean. It is unfortunate that I am compelled to use your mental concepts to think with. You are giving my thoughts a verbal twist peculiar to yourself. You see, Rawley, I can correlate your fugitive reactions to a given phenomenon with everything experienced by you from the day of your birth. By simply tuning in on your thoughts I can get your—your slant. Not merely your thought images, Rawley, but all the little twists and turns of your familiar speech. Fortunately you have telepathic powers, too. Somewhat rudimentary, but adequate."

The frog's eyes quivered. "Don't glare at me, Rawley. I have no intention of harming you."

"You harmed her ," I groaned.

"I harmed—Oh, I see. The girl, eh? We propagate by fission, so we've been spared all that. I didn't harm her, Rawley. All I did was diminish her mass. I had to do that to warm myself.

"Rawley, I was almost gone. I can stand a little cold, but that liquid air—"

"You did what to her?"

"Diminished her mass. Now keep your shirt on, Rawley. I need the glow to warm me. Needed it badly. For real warmth there's nothing like the radiant energies imprisoned in kalium. The bodies of terrestrials are ideal sources of heat in all respects; not only because they contain kalium, but because the other elements of which they are composed are among the easiest to tap.

"No harm done, you understand. I can radiate back subatomic particles at any time. All I did was squeeze out the radiations in a soft, glutinous mass. You don't have to bombard atoms or surround them with water-jackets to strip them, Rawley. With a little patience you can squeeze out their energies the way you squeeze toothpaste from a tube.

"My body has soaked up a fine, tingling warmth from all those frozen terrestrials. They are mere atomic husks now, but perfectly preserved and restorable at any time."

I scarcely heard it. Something was happening to the ship. Beneath my feet the deck was unmistakably swaying, and there were twangings and creakings all along the passageway which could only mean one thing.

The ship was in motion!

The frog had noticed it, too. It stiffened abruptly and cocked its head as though listening, its stalked eyes squinting shut.

In paralyzed astonishment I stood staring at the vibrating overhead, wondering what in hell it could mean. Had one of the frozen crewmen regained the use of his limbs and attempted an emergency take-off? I strained my ears, but could detect no atomotor drone, or other indication that we were rocketing upward from the crust.

"No, Rawley," the frog's voice came again, vibrant but strained. "No, we are not leaving the planet. I think I know what is happening. Rawley, you have an instrument which enables you to see the ship as though it were being viewed from a distance by someone out on the planet. Horiz—horizonscope. Suppose we see for ourselves."

We descended in the jacket-lift together, the frog bracing its knees precisely as the commander had done long ago in another world.

I don't know how I lived through the next ten minutes. When I stood in the control room and looked in the horizonscope I saw a sight which I shall never forget if I live to be a hundred.

On both sides of the ship were dozens of froglike shapes moving in single file, their bodies bent nearly double as though they were straining at the leash.

All about them swirled steamy vapors and flickering tongues of flame. A blood-red sun, so gigantic that it spanned a fifth of the sky, hung like a vast, glowing eye directly overhead, dazzling my pupils as I stared. Even in the horizonscope it seemed huge, blinding.

The scent was weird beyond all imagining—weird and unutterably terrifying.

"Rawley, they are moving the ship. They are using magnetic tow lines and making a mighty good job of it."

"Where—where are they taking us?" I gasped.

The frog's reply was utterly bewildering. "We'll label it terrestrial fauna—habitat group. We'll take the ship right into the museum. Large-brained bipeds from the third planet, stooping above their artifacts in perfectly natural attitudes. Magnificent.

"Mustn't let sunlight touch them. It's curious I didn't think of this when I absorbed their energies. My one thought was to warm myself, but necessity is the mother of invention. They'll honor me for this. I'll head the next expedition. My instructions were imbecilic. 'Observe all their habits and then mummify them.'

"What good are shriveled specimens? So long as sunlight doesn't touch them they'll keep this way for a thousand years. This one has been—helpful. Oh, enormously. Just as well I didn't tap him.

"I mustn't let him suspect that I couldn't—can't. I've absorbed too much radiance as it is. My energies are brimming over. He thinks I can still diminish his mass. Might have to kill him if he knew.

"Kill him. I could do that, of course. But I'd hate to lose one of these specimens."

It hit me all at once, with the force of a physical blow. There was something that the frog didn't know. It didn't know that I could listen in on its private thoughts. It thought it could shut off its mind from me. Hitting me also with force was the sudden realization that when in close proximity to it I had telepathic powers which were first rate, as good as its own.

Wait a minute—better. Because it didn't seem aware of what I was thinking now. So we were just animals to it, eh? Big-brained bipeds— specimens . I was edging away from it and toward the control panel, very cautiously.

Keeping my excitement down wasn't easy. There was a lot of anger mixed up with it, and more fear than a man of courage likes to own up to. I wondered how strong the magnetic tow lines were. Would they hold the ship if I blasted out all the rocket jets and started the atomotors ten seconds later?

It didn't seem likely. If I could reach the control panel nine-tenths of the battle would be won. Nearer to it I inched, and nearer.

The frog stirred just as my hand touched the rocket control. I swung down on it hard. Something in my brain started babbling as I swung my other hand toward the atomotor emergency bulb and splintered it with my naked palm.

The whole ship seemed to explode, carrying the top of my skull with it. I was no longer in a Mercury run spaceship screaming defiance at a frog.

I was far out in space between massive gaseous suns, red and blue and mottled, with island universes to right and left of me and a long-tailed comet sweeping down from a ragged hole on the sky.

When I crawled through the fence into my own backyard again I was bruised and partly numb, but the ship was plowing steadily through the void, and Mercury was so far away from it that it was a mere fly-speck mottling on the dull-corona-encircled disk of the sun.

The frog? Yes, it was still with us, but all the cockiness had gone out of it. It came to me, as meek as a lamb, and laid all its cards on the table.

It would be the specimen now. So long as we didn't cast it out through the air-locks to freeze in the void it would consent to be exhibited in every museum on Earth. Only the museums would have to be roofless, because it would need the sunlight.

It promised not to diminish the mass of a single human being on Earth. All it needed was our sunlight. Locked up in the Lyra and freezing to death it had been compelled to tap the nearest energy source, which happened to be us.

But on Earth it would tap the sunlight. It pointed out that the sunlight falling on one square foot of Earth would keep one of our big power plants running for a year, if we knew as much as the Mercurians did about radiant heat.

"I'll be no trouble at all, Rawley. And if you wish, I'll show you how to convert sunlight into useful energy. You won't need so many cyclotrons then. Before I'd monkey with anything as unpredictable as a skinless atom I'd go jump in a lake."

I was no longer listening. There was something I had left unfinished and it suddenly seemed more important to me than anything a frog could say or do.

Going down in the jacket-lift to Sylvia I kept trying to recall just how I felt when it had cheated me out of something I was entitled to.

It didn't seem right to leave a kiss dangling in midair, and I was sure that Sylvia was feeling frustrated, too.

She was. She came into my arms in utter silence, and we did the kiss up brown, and stored it away in our memories for when we were eighty-eight.

"Darling," she said. "I'm glad we thought of that."

I felt better almost at once. They had sent me out from Earth with a pat on the back and a commission, and I was returning with the commander's niece in my arms and a story in my brain which the news syndicates would certainly want.

I'd ask a good price for it. Lunar honeymoons were expensive, and although Sylvia wasn't extravagant she liked orchids as well as the next girl and was just the right height to wear sables with grace.