Old Kelvin Martin strained futilely against the rope that held immovable his thin wrists. A crimsoned bruise raced across his forehead where Vance had slugged him with a heavy hand.

"Don't be a complete fool, Vance!" he said harshly. "That machine can't bring you anything but trouble!"

The scientist's burly assistant glanced wearily up from where he coupled heavy batteries in series at the rear of the glittering machine that entirely filled one corner of the windowless room.

"Shut up," he said tonelessly.

Kelvin Martin sagged back in sheer futility, felt a deadly numbness creeping through his extremities from the tightness of his bonds. He watched the other out of eyes faintly fearful and desperate.

"I'll make a deal, Vance," he said finally. "I've got about eight thousand dollars in the bank; free me, don't try to use that machine, and the money is yours!"

Jon Vance's laughter was brittle and scornful.

"Eight thousand!" he sneered. "Hell, I've seen those snapshots you brought back! Any one of those gems the 'other people' wore would bring that. And I intend to bring back all I can carry!"

Kelvin Martin shivered, remembering the restless cruelty that had lain in the creatures he had found with his machine. There was still a dull ache along his ribs where a needle-like ray of terrific energy had seared.

"They aren't human, Vance." He tried to speak quietly, endeavored to drive his point with impersonal logic. "They are of a fierceness and cruelty such as you couldn't comprehend. And with their superior weapons, they'd subjugate the entire world in a matter of days."

"Hooey!" Jon Vance spat insolently, patted the .45 automatic at his hip. "I think I might do a bit of subjugating myself."

He tested the batteries.

"I don't know how it works, Martin," he said briefly. "But I don't care, just as long as it makes me rich."

Of course, Jon Vance did not fully understand the machine; even he, himself, had trouble at times in comprehending the space-warping propensities of the machine he had built over a period of three years.

He knew only that the machine warped itself and its occupant into another universe—a galactic maelstrom of whirling suns and gigantic planets—onto a world where he had met a race of living beings that seemed to be super-endowed with unhuman hate and cruelty.

He felt the sickness of futility within him when he remembered the one time he had invaded that other space. He had stepped from the machine and been greeted, cautiously but cordially, by those great-headed super-beings. For days he had been entertained and shown the weird sights of that alien planet. And it wasn't until he woke one night, to see the curious machine hanging motionless over him, its pale blue aura covering his sleeping couch, that he realized that he was being drained of his knowledge subtly every night.

He had raced from his sleeping room, fought with the single gun he had taken with him, blasted his way through the screaming mob that tried to hold him captive. He had fought down the long stairs, through the palace door, and had fled into the night, pursued by the men who had protested their friendship.

With his last bullet, he had killed the High-Priest, stepped over the prone body, and lurched into his machine. His fingers had flicked the levers on the control panel; there was the instant hum of purring power—and then the machine had whisked him back to his own planet.

He had sat for hours in the machine, too drained of energy to move, knowing that only a miracle had saved his machine's secret from the aliens that had planned to use it for an invasion of another space.

But now, because of the stupid greed of Jon Vance, because the man did not realize the slavery and terror the aliens would bring to Earth, the machine was gone—and he was a prisoner in the laboratory room.

He made one final desperate plea.

"All right, Vance, if that's the way it is," he said tiredly. "But if anything goes wrong, destroy that machine; those monsters will use it to invade our system."

Jon Vance whistled thoughtfully, watching the scientist out of shiny eyes, his heavy features drawn into a frown. Then he shrugged.

"If things don't go as planned, maybe I can make a deal," he said. "After all, I always did think I'd like to be a big shot."

"You couldn't!" Sheer horror froze Martin into motionlessness.

"The hell I couldn't!" Jon Vance stooped, edged through gleaming wires, seated himself at the machine's controls.

He twisted a rheostat, closed a switch, grinned at the supine scientist. Kelvin Martin said nothing more, but there was a grim determination replacing the panic in his faded eyes.

A vacuum tube swelled with coruscating colors, and a nimbus of light grew from a lacing of wires around the edges of the machine. There was a dull throbbing in the close air, a rushing sense of the releasing of terrible, unknown power. A misty curtain seemed to be drawing tight about the machine's outline.

Then the machine was gone from its platform, and Kelvin Martin was alone in the great, bare experimental room.

Kelvin Martin didn't move for seconds, then he struggled into a sitting position. He fought the ropes with a silent doggedness that sent the hot blood pounding turgidly at his temples. His mouth gaped, as he strained and twisted futilely, and the panic in his eyes was a terrible force.

Then he sagged limply, realizing that the ropes were too well-knotted for him to release himself unaided.

"God!" he prayed.

He drew his legs beneath him, shoved himself back until his shoulders touched a side wall. Sitting there, he searched the room with feverish eyes for any object with a cutting edge. His heart sank, when he saw the bare sterility of the room. Without windows, without tools or furniture, there was not a thing in the room that could be broken or used to sever the cutting ropes at his wrists.

Kelvin Martin sobbed deep in his throat, glanced at the door, remembering how Vance had locked it and pocketed the key.

He remembered the cigar lighter in his pocket, tried to fumble it out, with the intention of burning his bonds. Dull horror pounded at his mind when he realized that his hands were completely numb, without the power of following the dictates of his mind.

He had no way of visualizing how long the treacherous Vance would be gone, no way of knowing whether the man would return victorious. But clear reasoning told him that the monstrous people of the other world would slay Vance, then use Martin's machine as the doorway through which to pass their conquering hordes. Too, the machine would serve as the model for more carriers.

He straightened at the thought, memory struggling for expression in his mind.

He followed the lines of the walls, leaning against them for support, edging forward with agonizing slowness by jumping his tied feet. Perspiration dotted his white face, and his thinning hair lay tight on his small head, but slowly the smile broadened on his lips.

At last, he rested against the wall, then gently slid to a seated position. He tested his bonds again, ceased the futile struggle almost immediately.

He sat for a time, then lay back and stared at the ceiling. He thought of many things in those passing moments, thoughts of his dreams of giving scientific miracles to the world, of having his bust in the Hall of Fame, of people he had known, and things he had done.

Regret shadowed his memories, when he remembered things that he had left undone and unforgiven. Then he shrugged a bit, lay breathing quietly, waiting for the machine to return.

He felt the sensation of released forces a few seconds before the machine reappeared. He sat, drew his legs to his chest, scooted back a few feet. He waited, content, wondering just what would happen. He was smiling when the machine and its unhuman occupants whisked out of nothing into shadowy being. One glance they had of the smile on his tired face—then the very air seemed to explode with gigantic twistings and loopings of unleashed forces.

For Scientist Kelvin Martin had remembered one scientific fact from his college days. He had recalled that two material objects may not occupy the same period of space.

And sitting, bound, on the machine's platform, he had awaited the coming of the Frankensteinian monster he had created.