Descending even more cautiously now, they neared the scene of activity.

"My plan is this—to get aboard and find out where they're going!" said Stoddard, through shut teeth. "What do you say?"

"Lead on!" said the professor.

So they continued down, neared the resting-place of that strange craft, and, under shelter of the moonlight shadows, stole through the confused ranks surrounding it and crept aboard.

* * * * *

Stowing themselves into the first likely niche that offered—a narrow cubicle behind a flight of metal stairs—they waited, scarcely daring to breathe for fear of being discovered.

Fifteen minutes passed, a half-hour, when suddenly sounded a rasping of doors that told them the rocket was being sealed.

Then came a roar, as of some mighty blast beating down upon the frozen earth, followed by a lifting, rushing sensation—and they were flung violently to the flooring.

The pressure ceased in a moment, however, to be supplanted by a buoyant, exhilarating sense of flight. It increased, and they judged they must be traveling at great speed.

Glancing at the luminous dial of his watch, Professor Prescott saw that it was a quarter to ten.

"Well, we're off!" he whispered. "And where, would you guess, are we headed?"

"I wouldn't guess," Stoddard whispered back. "From the way we're riding, it might be Mars! We must be making hundreds of miles an hour."

"Or thousands! Who knows?"

They crouched there in their cramped niche, scarcely even whispering now, as the tense minutes passed.

* * * * *

Suddenly the motion changed. They seemed to be dropping.

Another moment or two, and with a slight jar the rocket came to rest.

"Well, we're here, wherever it is," said Stoddard, stirring.

"Yes, undoubtedly," the professor agreed. "And the next move?"

"I think we'll let them make that."

They were not long in doing so. There came the sound of doors rasping open, of footsteps echoing on metal stairs and corridors. Once a giant Cossack passed within four feet of them. But at length, all was silent within the rocket.

"Now, then, suppose we have a look around," said Stoddard, stepping out.

"Right," agreed his companion, following. "I'll admit I am mildly curious to know what corner of the earth we've been transported to."

They proceeded down the dim-lit corridor the way they had come, descended a flight of stairs and headed along another corridor—to pause suddenly and gasp with astonishment. For through the door whence they had entered the rocket poured a flood of sunshine.

* * * * *

Stoddard stared at it a moment incredulously, and then glanced at his watch.

"Ten o'clock, I make it!" he muttered. "Am I crazy, or what?"

"No, I hardly think so," smiled Professor Prescott, recovering from his own surprise. "It is merely that we are in some part of the world quite a few thousand miles removed from India. Back on Kinchinjunga, it is still ten o'clock at night, but here, it is quite obviously daytime."

"That must be the explanation," Stoddard agreed. "But it certainly gave me a start at first!"

Approaching the door, followed by the professor, he peered cautiously out, to confront a desolate stretch of scrubby growth, hemmed in by a background of rugged mountains.

"Now where the devil would you say we are?" he demanded, gazing around perplexedly.

"Either in the United States or in Mexico," was the astonishing reply.

"But how can you say that?"

"Because it must be some place approximately twelve hours distant from India in time, to judge from the sun, which is not far past the meridian."

"But why not Australia, for instance?"

"Because Australia is too far. It would be three o'clock tomorrow morning there, since it is ten o'clock last night now in India."

* * * * *

Stoddard pondered this a minute, then admitted its correctness.

"All right, then. Assuming that we are somewhere on the North American continent, the next thing is to give Krassnov the slip; otherwise it won't be big enough for all of us!"

And that Professor Prescott conceded readily enough.

But before making any further move, they looked over their surroundings carefully, to satisfy themselves none of their late captors were in view.

"They're evidently somewhere on the other side of the rocket," Stoddard concluded at length. "So let's make a break for it while we've got the chance."

"Lead the way!" said the professor.

"O. K., here we go!"

And, stepping through the door, they dropped to the ground and raced off under the glare of the burning sun toward the rugged mountains that loomed ahead.

* * * * *

For a hundred yards or so they were able to keep the rocket between themselves and the Russians but soon the ground sloped up to such an extent that they realized they must be in full view.

Dropping behind the scant shelter of a scraggly tree, they turned and glanced down—and there, beyond the rocket, they could now see a group of men standing around outside a small wooden shack, shouting and gesticulating in their direction.

"Damn it, they've seen us!" muttered Stoddard.

"But why don't they come after us?" queried Professor Prescott.

The answer came even as he spoke, for out of the shack rushed the tall figure of the prince, in his hand a pair of binoculars which he raised to his eyes.

Whether or not be spotted them, an instant later he turned and uttered a command, and two huge Cossacks sprang to the pursuit.

"There's nothing to do now but run for it!" cried Stoddard, leaping to his feet.

The professor followed and they plunged on up the slope, bullets from their pursuers' pistols and the rifles of those below kicking up the dust around them. But either because the aim was bad or the targets difficult, they escaped unscathed.

As for Stoddard, he wasted no time in firing back.

"Once we get in those mountains, we're safe!" he gasped, as they struggled on. "How are you, Professor—all right?"

"No holes in my skin so far!" came the panting answer.

Five desperate, dodging minutes passed.

Glancing over their shoulders, they saw that the heavy, stolid Cossacks were losing ground. And ahead, tauntingly near now, loomed a thickly-wooded slope that meant the beginning of big timber—and safety.

Another five minutes—each second an hour—and they had gained it.

* * * * *

But there was no pausing yet, they could hear the Cossacks crashing on like determined blood-hounds behind.

"No need to climb any more!" exclaimed Stoddard, half breathless. "We'll edge along, keep in the trees, and try to throw them off."

The older man said nothing; merely gritted his teeth. This climb had told on him more than anything he had experienced on the cruel slopes of Kinchinjunga.

As they struggled along now, sometimes it seemed that they had thrown their pursuers off the trail, or completely outdistanced them, but always a moment later they would hear again the crunch of the Cossacks' boots on the dry undergrowth.

So the grim flight continued, mile after heart-tearing mile, and Stoddard was beginning to realize that the professor couldn't keep on much longer—had just about decided to stop and shoot it out with their pursuers—when suddenly there came a sound that brought new hope to him.

"Did you hear that?" he gasped, pausing.

"It—sounded like—a car!" panted his companion.

"Right. And that means there must be a road through here somewhere! But where?"

"Listen." Professor Prescott pointed to the left. "The sound seems to be coming from over there."

And sure enough, from the left came a wheezing grind of a car making a heavy grade.

"Near, too," decided Stoddard. "Come on—let's go! We've got to head it off. It's our only hope, except—"

With relief, he shoved his automatic back into its holster and led the way in the direction of the now rapidly nearing car.

* * * * *

A hundred yards they had made, up a slight rise, when there spread before them a rutted mountain road, and on it, in full view, was a laboring Ford of ancient vintage.

Over the wheel hovered a lanky, leathery native, and beside him sat a small, plump woman who looked as though she might be his wife.

They were almost to the top of the hill when Stoddard hailed them.

"Say!" he said. "Give us a ride, will you? We're lost."

"Keep on, Henry!" he heard the woman urge. "I don't like the looks of 'em."

Americans! Well, thought Stoddard, they were in the United States, anyway. That was something. And he didn't exactly blame the good woman for her suspicions. They must look pretty wild, at that, with their two-day beards and tattered clothes.

"Sorry," spoke up Henry. "Missus says no. She knows best. 'Sides, it ain't fur to Martin's Bluff. You kin make it in an hour."

"But say, wait a minute!" They were running along beside the wheezing car now. "We've got to get there in a hurry. We'll pay you."

Henry pricked up his ears at this, but his wife shook her head.

"Keep on!" she urged. "They may be bandits!"

* * * * *

Whereupon Stoddard drew his automatic, for there was no more time to argue.

"Stop!" he commanded. "You'll take us, understand? I'll pay you well!"

"See, I was right!" screamed the woman. "Bandits! Bandits! Oh, Henry—save me!"

Wildly she clung to him, as Stoddard mounted the running-board, but before he could make another move, Professor Prescott gasped out:

"The Cossacks! Quick!"

And jumping down, he wheeled to face the two leering Russians, not forty feet down the road. Pistols levelled, they were advancing stolidly.

Stoddard half-raised his own weapon, then turned to see if the car was within range of the return fire it would bring. It was—but not for long.

With a furious chattering of bands, as Henry gave it the gas, the decrepit vehicle gained the top of the hill and disappeared from view down the far slope, and the last thing he saw of it was a dusty plate flapping under its tail-light.

It was a Texas license!

Then, turning back, he lifted his automatic; but it was too late. The Cossacks were on them.

In answer to a guttural command, he dropped the weapon and raised his hands, as the professor had already done.

* * * * *

Two hours later, they were back at the rocket.

Led into the shack—which was furnished inside like an Oriental hunting-lodge—they were confronted at once by Prince Krassnov.

Though his aristocratic features were immobile, it was obvious that he was in no amiable frame of mind.

"So, my friends!" he exclaimed. "I leave you in India, and meet you again in America, all within a matter of hours. It is but an example of our modern progress, is it not?"

They made no reply.

"Ha! You are not sociable, after enjoying my hospitality, my transportation? Then suppose we—as you Americans so quaintly say—call a spade a spade! I gave you your chance. You declined it. And what is the result? My beautiful Diamond Thunderbolt, my immeasurable treasure, is buried forever."

"Through no fault of ours!" put in Stoddard.

"But buried nevertheless, and my adopted kingdom in revolt. Yet do not think I mourn too much, my friends. Though the game is what you call up, my plans shall go on. Here and elsewhere in the world, where we have sub-headquarters, are billions of dollars' worth of diamonds—supplies for years ahead. We shall not suffer. But you—Professor Prescott and Doctor Stoddard—I have a very interesting fate in store for you. How would you care to make a little scientific expedition to Mars, say?"

"Mars?" gasped the professor.

"Yes, or Venus, or even Jupiter, not to mention the moon! Or how about the sun? That would be an interesting sphere for exploration."

"We don't know what you're talking about," said Stoddard growing nettled. "Why mince matters? Call a spade a spade, if you're going to! What do you propose to do with us, now that you have us in your power?"

The prince paused, drew forth a long Russian cigarette from an exquisite platinum case.

"I propose," he smiled, when he had lit it, "to turn over my rocket to you, my fellow scientists, since I shall have no further use for it and it might be embarrassing to be found with it in my possession."

And the way he proposed to turn it over to them, as they had already suspected, was to lock them in it and fire it off into space.

* * * * *

Within the hour, the man's diabolical plan had been put into operation.

Led to the rocket, the luckless pair were locked within a small metal room somewhere within its recesses. There sounded again the peculiar rasping that told them its doors were being sealed. And then came the roar of that mighty exhaust beating down.

There followed the lifting, rushing sensation they had experienced before, and again they were flung violently to the flooring by the force of the upward impulse.

When the pressure slacked, they staggered to their feet and groped around the dark, stuffy little room.

"Well, this is the end, I guess," sighed Professor Prescott. "I had never thought," with a grim attempt at humor, "that I would meet quite such a scientific fate as this!"

"Nor had I!" Stoddard agreed. "But I'm not quite ready to cash in my checks yet. The game isn't over!" He was pacing around the room, knocking on the metal walls with something that gave back a strident ring. "Have you any idea what composition this stuff is?"

* * * * *

The professor rapped on one of the panels; felt of it.

"Aluminum, I would say."

"Nothing so lucky! If it were, I could cut it like cheese. But duralumin, probably, a very light, strong alloy; and what I have here is a hunting knife with a can-opener on one end! If I'm not mistaken, we'll be out of this sardine box before long."

Whereupon he applied himself to the thin metal wall of their cell, working determinedly, while Professor Prescott held his cigarette lighter for a torch.

"You see, duralumin yields to heat, like aluminum," he exclaimed, as finally his knife thrust through. "Now then, let's get the can opener working."

The progress was slow but sure. Within an hour, he had cut out a jagged section some two feet square, through which they squeezed into an equally dark corridor.

"Now then!" Stoddard's mood was exultant. "There must be switches around here somewhere. There were lights, I remember, so let's find them. Once we get a little light on the subject—"

"Here!" called the professor, who had groped down the corridor with the cigarette lighter. "How's that?"

As he pressed a switch, a row of small bulbs glowed overhead.

"Fine!" was the answer. "Now let's see if we can find the engine-room, or whatever they call it."

* * * * *

Jubilant now, they continued on down the corridor, which ended in a flight of stairs.

"I fancy it must be below," said Professor Prescott. "From what I have seen of experimental models, the propulsion impulse must originate from the base."

So they descended the stairs, entered another dark corridor, found another switch and pressed it, and thus they proceeded, lighting the interior of the rocket as they went. And as they descended, the roar of the exhaust increased in volume, indicating that they were nearing its source.

Presently they entered a large, circular room with an illuminated dial at the far end. Drawing near, they saw a confusion of instruments that for a moment left them dazed.

While Stoddard studied them in bewilderment, Prescott circled the room till he found a switch. Pressing it, he produced a brilliant flood of illumination.

"Now then, let me have a look at this," he said, returning to the dial. "Professor Goddard once explained to me the workings of one of his experimental models. The motive force must be some liquefied mixture, possibly oxygen and hydrogen. Some of these instruments—most of them, in fact—must be valves."

He touched one, turned it, and the rocket responded with a sickening burst of speed.

"No, that won't do! We're going plenty fast enough now!"

He touched another, and they slacked off dizzyingly.

"Well, there are two controls, anyway. Now then, how do they steer this thing? That is the next problem we must solve."

But though he touched this instrument and that, producing weird effects, their course continued in the direction set. And meanwhile, they were hurtling outward through space at a rate of speed he knew would presently carry them beyond the gravitational pull of the earth.

Then, as he grasped and swung down a curious lever that worked in a quadrant, they felt a violent lunge to the left, and for a moment it seemed they would shoot to the ceiling.

"Good God!" gasped Stoddard. "What's happened?"

"Nothing—only that I've found how to steer this wild steed!" cried the professor, exultantly.

* * * * *

It was really quite simple, he explained, as he eased up on the lever. In application, it was a development of the gyroscope principle, that a wheel revolving freely within a freely suspended frame tends to make the frame revolve in the other direction.

"You see, the rocket is the freely suspended frame," he went on, "while this lever controls a gyroscopic wheel somewhere. To set it spinning to the right causes us to turn to the left, and vice versa."

"But you almost stood us on our heads, a moment ago! How did that happen?"

"Simply because I threw the lever too far to the right. We are in interstellar space, obviously, where every change of direction involves an adjustment of equilibrium."

And if Stoddard didn't exactly understand, being first a secret service man and only secondarily a scientist, at least he showed his ignorance no further. If the professor could bring this astounding machine back to Earth, that was all he wanted.

Prescott said he could, he thought, providing they had fuel enough left. So for the next few minutes, while the younger man held his breath, the professor labored with the various instruments on that complicated dial.

"Now then, I think we're headed back," he said at length, relaxing. "But we've got to have visibility, otherwise we will land with a velocity of about twenty thousand miles an hour, which is what I figure we're making at the present time."

"Good Lord!" gasped Stoddard. "I'll say we've got to have visibility! Wait a minute! Let me look around!"

He searched the room for further instruments—to find nothing that in any way met the purpose.

But even as he returned dejected, the professor cried out:

"Here—I've got it! Take a look at this!"

Bending over a small table beside the dial, Stoddard saw mirrored, in its ground-glass surface a hazy circular panorama that at first had no significance. But as he continued to peer down upon the scene, certain familiar aspects loomed out. It was the Earth—and what he was looking at was a view of the North and South American continents!

* * * * *

For some moments Stoddard stared at this amazing panorama in silence; saw it grow rapidly clearer, as the careening rocket plunged like a giant shell toward the earth.

"My God!" he whispered at length in awe. "Do you think you can ever check our speed?"

"I think so," the professor replied, busy over his instruments. "But where do we want to land? How do we know what state we were in?"

Whereupon Stoddard told him of that Texas license plate.

"But we don't want to land anywhere near that fiend Krassnov," he added, with a shudder. "I suggest, if it's possible, that you pick out some aerodrome, preferably in the western part of the state—for if I remember my geography, Texas isn't mountainous in the east."

"I will do the best I can," said Prescott, grimly.

There followed tense minutes as the panorama in that ground-glass narrowed and grew more intense. Now they could see only North America, now only the United States and a portion of Mexico, and now only Texas.

"Back—back!" cried Stoddard, as the rugged land loomed up, spread into a panorama of towns and ranches. "We're descending too fast! We're bound to crash, unless—"

But already the professor had touched the ascending valve and swung the steering lever.

Up they zoomed again. Once more a portion of Mexico was visible on the glass, and along the international border now they could see a winding thread of silver.

"The Rio Grande!" exclaimed the young geologist. "Just follow it up toward its source till we come to El Paso. There'll be a landing-field there."

"Yes, undoubtedly." The professor was working in abstraction over the unfamiliar controls. "Now if I can just hold us on our course...."

* * * * *

He succeeded, and presently a white city gleamed over the curving rim of the horizon to the northwest, the tall chimneys of its smelters throwing long shadows from the lowering sun beyond.

In a minute or two they were over it, at a height of perhaps twelve miles—and now, as they began descending, its patchwork of buildings and plazas unfolded like some great quilt below.

"There's the field!" cried Stoddard, pointing in the glass to a wide clear space on the outskirts. "Can you make it, do you think?"

"We'll know soon!" was the grim answer, as Prescott worked frantically now with his valves and levers. "It's a matter of balancing off our flow of gases, of holding up buoyancy to the very last. A little too much, or not enough, and—"

Breathlessly, as they descended, Stoddard peered into the glass. Now a scene of excitement was visible below. Figures could be seen gazing up, waving their arms, running about this way and that.

"They must think they're getting a visit from another planet," said Stoddard. "Or that the end of the world has come!"

"Maybe it has, for us!" agreed the professor, gravely. "I'm afraid we're going to crash. I can't seem to—"

Whatever he was going to add was lost in a sudden, rending concussion that flung them violently down, and plunged the room into darkness.

* * * * *

Staggering to his feet a moment later, bruised and shaken, Stoddard gasped out:

"Professor are you there? Are you all right?"

A groan answered him, and for a moment his heart sank, but then came the reassuring call:

"Yes—all right, I guess. And you?"

"O.K. Let's get out of here, quick!"

An ominous hissing sound beat on their ears, as they groped their way toward the door. Evidently escaping gases from the deranged mechanism, thought Stoddard. The floor rose at an angle, indicating that the rocket was half over on its side.

They found the door, and struggled along the twisted corridor toward a flight of stairs that would lead below; found it, descended, and groped along another dark corridor, seeking an exit; when suddenly, around a bend, daylight confronted them, and to their joy they saw that one of the main doors had been burst open by the impact.

Approaching it, they peered out—to be greeted by an awed group of officials and mechanics from the field.

As they climbed through, dropped to the ground, the group retreated, taking no chances.

"Back!" called Professor Prescott, warning and reassuring them with a word. Then, turning to his companion: "Come on, Jack—run! This thing is likely to explode at any moment."

Following this advice, Stoddard raced from the rocket with the rest.

At a safe distance, he turned and peered back—to see it standing there at a crazy angle, dust and fumes issuing from under it in a blast that was hollowing a deep crater to the far side.

Even as they looked, the strange craft quivered, tottered, and fell over on its side, and the next instant was enveloped in a blinding sheet of flame that brought with it a dull detonation and a blast of dazing heat.

The party backed still farther away.

"A nasty mixture, oxygen and hydrogen," muttered the professor, feeling of his singed eyebrows. "We got out of there just in time, Jack."

"I'll say we did!" Stoddard agreed, with a shudder.

* * * * *

By now the higher officials of the field were on the scene, among them a number of Army men.

Curiosity ran high, not unmingled with indignation. Who were these strange visitors? Where had they come from? What did they mean by endangering the lives of everyone, with their damned contraption?

Inquiring for the commandant, they were taken to him—Major Clark Hendricks, U.S.A.—and Stoddard briefly outlined their astounding story, producing credentials, whereupon a squadron of fast military planes was assembled.

From the way they described the mountainous region where the rocket had first landed, mentioning the town Martin's Bluff, that Henry of the ancient Ford had named, the major declared that it must have been the Guadalupe Mountains a hundred miles to the east—and sure enough, a government map showed such a town there.

So it was that presently the squadron lifted into the late afternoon skies, with Major Hendricks in the leading plane, accompanied by the two weary adventurers.

Swiftly the squadron winged eastward. They reached the mountains in less than an hour, and circled them in search of that little wooden shack which Prince Krassnov and his Cossacks had made their rendezvous....

* * * * *

It was like finding a needle in a haystack, and for a time Stoddard despaired of success. But those rugged mountains were an open book to the planes circling high overhead, and with Martin's Bluff once located, the rest was not so hard.

At last, as twilight was falling, they found the shack and brought their planes to rest near it.

But as the party approached the shack, after posting a heavy guard over their planes, they saw that it was deserted.

This, after all, was only what Stoddard had feared, but nevertheless they forced their way inside—and there, had Major Hendricks had any doubt of their story, it was dispelled.

As Stoddard had told them, it was furnished like an Oriental hunting-lodge, with evidences of the recent occupation of the Russians on all sides.

But where were they? Had they got away or were they hiding somewhere?

Proceeding from room to room until they had searched it thoroughly, the party paused baffled.

But not for long, for suddenly Stoddard discovered something that gave him a clue. It was a barred door, within a closet, covered over with clothes and uniforms so as to be fairly well concealed. On battering it in, they found that it led into a passage below.

* * * * *

As the party entered the passage, leaving further guards above, it became obvious that what they had found was the shaft of an old mine.

It led down abruptly, for a while, then more gradually, with many windings and twistings, and ending presently in another barred door.

This they in turn battered in—to be greeted suddenly by a volley of rifle-fire that dropped three of them in their tracks.

Stoddard was one of those who fell.

Bending over him, Professor Prescott lifted up his head.

"Jack!" he called. "Where are you hit? Answer me!"

"I—it seems to be in the shoulder," came the weak reply. "If you've got a handkerchief—"

The professor produced one and staunched the flow of blood as best he could, working with the aid of his flashlight.

Meanwhile, ahead, the crash of pistols and rifles continued to split the stillness of the passage, as the attacking party pressed forward.

"There—that does it!" gasped Stoddard, at length. "Help me up. I'll be all right."

Prescott steadied him to his feet. They continued on.

* * * * *

Now the firing ceased, and in a moment Major Hendricks appeared, at the head of his party.

"Well, we've got them," he said, saluting Stoddard. "How are you, old man?"

"All right," was the gritted reply. "Let's have a look at them."

A flashlight was swept across the stolid group of Cossack prisoners, but as Stoddard peered into one face after another, he realized that Krassnov was not among them.

"You haven't got the leader," he said. "See here, you birds," he addressed the Cossacks, "where is he, eh?"

If they understood, they gave no indication of it, but shook their heads sullenly.

"Well, damn it, we'll find him!" Stoddard wheeled and strode past them. "Give me three or four men, Major. I'll smoke out that Russian bear. He must be here somewhere."

Hendricks sent the main body above, with their prisoners, and gave him the men he wanted, putting himself at their head.

"You'd better go on up, too, Professor," said Stoddard, addressing Prescott. "You've risked enough, in my behalf."

But the older man shook his head.

"No, I'll come along, if you don't mind," he insisted. "I want to see the end of this thing."

* * * * *

It was an end that came with dramatic suddenness.

Pausing before a barred door some fifty paces down the passage, they were debating what their next move would be—when suddenly it was flung open.

"Come in, gentlemen," came a suave, ironical voice. "Sorry my servants were so uncivil."

In the glare of light from beyond, Stoddard and the professor saw that it was Prince Krassnov.

He stood there unarmed, smiling.

"Is this the fellow?" rasped Major Hendricks, his automatic levelled.

"It is," said Stoddard.

Slowly, cautiously, they followed the man into the room, which in reality was merely the end of the passage sealed off, though its walls were richly panelled and it was luxuriously furnished.

Pausing beside a small, heavy table, he swept his hand over it, indicating a heap of rough diamonds that must have represented millions.

"Merely a fraction of my treasure, gentlemen," he told them, with a deprecating shrug. "I hadn't quite finished storing away the last shipment, when you interrupted me."

He strode to one of the walls, drew out a small drawer from a built-in cabinet and dumped its glittering contents on the table with the rest.

All around the room, Stoddard noted as he stood there swaying, were other cabinets dotted with the knobs of similar drawers.

"And this, gentlemen, is but my American sub-headquarters," the Prince went on. "In Siberia, in Brazil—but why bore you with the multiplication of my now useless wealth? Tell me, instead, my good friends—Professor Prescott, Doctor Stoddard—how come you back here, after I saw you safely on your way earlier in the afternoon?"

"Because I happen to have a knack with can-openers, and my colleague is rather adept with machinery," Stoddard told him, "while Major Hendricks here is quite a hand with geography, not to mention aviation."

* * * * *

A question or two, which they answered briefly, and Krassnov had the story.

"Ah, my poor rocket!" he sighed. "But it is fate, I suppose; Kismet, as the Turkish say. Still, I deserved a better fate than to be captured by a pair of American professors, when the secret service of the world was on my trail."

"Then cheer up!" said Stoddard, gritting his teeth to keep back the pain of his throbbing shoulder. "For I have the honor to represent Washington in this case."

At that, the prince scowled darkly for a moment. Then he brightened.

"Kismet again! I might have acted differently, had I known that, but—well, I drink to your success, Doctor Stoddard!"

Whereupon, before they could restrain him, he lifted a vial from a shelf over one of the cabinets and downed its contents.

"A diamond-dust cocktail!" he smiled, replacing the vial. "The most expensive, even in your country of costly drinks—and the most deadly!"

But Stoddard knew, as the doomed nobleman stood there facing them in stoic triumph, that diamond dust in the human system was as slow as it was deadly, and that the desperate gesture had been futile, so far as justice was concerned.

There would be ample time, in the weeks Prince Krassnov of Imperial Russia still lived, to round up his international allies and stamp out the remnants of their amazing ring of diamond smugglers.

While as for Professor Prescott, he was thinking with what amazement the members of his expedition back on Kinchinjunga would receive the cablegram he would dispatch that night, informing them that Stoddard and himself were safe in El Paso, Texas.



The Slave Ship From Space

By A. R. Holmes



[Sidenote: Three kidnapped Earthlings show Xantra of the Tillas how "docile" Earth slaves can be.]

Twice that night the two young men had seen the thing, and their hour for turning in had long since passed as they lay half reclining on the ground by their campfire waiting, hoping that it would return once more. Their interest in the strange visitant had completely banished all sensations of fatigue from a full day of vacation fishing in the cold Adirondack streams among which they were camping for that month.

They had discussed the appearance until there was nothing more they could say; and now as for the last hour, they watched in silence, only moving to knock the dottle from their pipes and to get fresh lights off the splinters they stuck into their slumbering fire. The velvet night was now at full reign, and the myriad stars in their familiar patterns leaned close—brilliant jewels for man to share but never pluck.

Jim Wilson had seen the thing first—a pinpoint of cherry red that moved upward in a perfect arc against the brilliant white constellations of the east. As it rose, it grew perceptibly larger, to dwindle again as it arced over the western horizon.

Nearly an hour later it had appeared again; but this time, when halfway up the skies, it had changed its direction until it was heading directly over the spot where the two thrilled campers were watching; and as it approached they saw its color fade slowly until it had disappeared completely from sight among the inky patches between the stars overhead. For minutes the two were not able to locate it—until Jim, once again, had pointed to a faint red spot that grew in color and intensity as it drew away from the zenith. Once again it had disappeared over the rim of the western world—and from then on there was no thought of sleep in the minds of Jim Wilson and Clee Partridge. They were watching the skies, hoping it would return.

"What was the thing?" Jim Wilson exclaimed suddenly with exasperation. "I've been racking my brain, Clee, but nothing I can think of makes sense. It couldn't have been a plane, and it couldn't have been a meteor. And if it was a fire-fly—well, then I'm one too." He paused, and looked at the other. "Any new suggestions?" he asked.

"Me—I still think it was a space ship from Mars or Venus," Clee Partridge answered drily; "searching for a couple of good Earth-men to help 'em out of some jam. You noticed the way it disappeared for a moment when it was overhead: it was looking us over."

"Then it'll be back," answered Jim, not to be outdone, "for it's not apt to find anyone better qualified. I, myself, would kinda like to take a joy-ride out through the Great Dipper."

* * * * *

Clee smiled and looked down at the luminous dial of his wrist watch. The two resumed their vigil, and there was quietness between them. For some time they lost themselves in the sparkling glory of the firmament, hardly moving, except to pull closer the collars of their flannel shirts against the increasing coldness of the mountain air.

And then for the third time that night the mysterious sky traveler sprang over the trees on the eastern horizon. Suddenly it appeared; both men saw it at once; and this time it made a clear, beautiful arc straight for the zenith. As it raised, it grew in size, a beautiful, delicate cherry star spanning the whole welkin. The two men got to their knees and watched it, breathless with fascination.

"Look!" cried Jim suddenly.

As had happened on its second appearance, the thing began to slow up and its color gradually faded as it drew directly overhead. By the time it should have reached the zenith it could no longer be seen. It had dissolved against the inky spaces above.

"It should come into view again in a moment," Clee said; "a little farther on, like the other time."

They watched, thrilled by the mystery of the midnight phenomenon. Minutes passed, but still it did not appear. Clee grew restive, and as his eyes chanced on his wrist watch he started violently and held out his arm for Jim to see. The radium-painted hands and dial were glowing with unusual brilliance.

Looking quickly into the skies again, Clee sensed something wrong; something different. For a moment he could not figure out what—and then it came to him. One of the great stars, one that he had been watching in its climb up the sky through the night, had disappeared!

* * * * *

He got excitedly to his feet, grabbed his companion's arm and pointed out this strange thing—and as he pointed another star blinked out and did not reappear.

"Something's happening up there," Jim said soberly. "I don't know what; but I, for one, don't feel quite comfortable."

He kept peering at the place pointed out, at a spot of black even darker than the inky sky; or did he only imagine it was darker? he asked himself. Soon the spot enlarged; became a distinct patch; then, growing still, obliterated one star after another around its borders. It made a pure circle; and before long the starlight glinting off its sides showed it to be a great, tinted sphere.

Swiftly it dropped down on the two men, and they watched it hypnotized, incapable of moving. It was only a hundred yards overhead when some presence of mind returned to Clee.

"Run, Jim!" he yelled, moving away. "It's coming straight down!"

Wilson came out of his daze and the two sprinted wildly for the path that led down the spur on which their camp was located. They had not made more than fifty yards when they heard a dull thud, and, turning, saw the great sphere resting on the ground with a slight rocking motion that quickly ceased.

A gully cut into the trail ahead, and when they reached it Clee grabbed his partner's arm and pulled him off to one side, where, panting with their sudden exertion, they wormed up to the brow and peeped over at their strange visitor.

* * * * *

The sphere stood in the starlight on the very spot they had been occupying when they first saw it. Right in their campfire it lay—a great, dark-red crystal shape perhaps fifty feet in diameter, whose surface sparkled with innumerable facets. It rested quietly on the ground, as if oblivious of the two routed men breathlessly watching it from a short distance. No ports or variations of any kind were visible to mar its star-reflecting sides.

"It must be some new kind of dirigible!" murmured Jim; "but why did it go and pick on us for its midnight call!"

"It's a space ship from Mars," answered Clee with a serious face. "They heard you, and're coming to take you for your ride. See?" he added quickly, pointing.

A large door was opening in the side of the sphere, and the illumination within threw a bright beam of amber-colored light in their direction. A metallic ramp slid out and angled down to the ground.

Breathlessly the two men waited to see who would emerge, but a long time went by without their catching the slightest sign of life within. The face of Clee's wrist watch was fluorescing brilliantly now, and moment by moment the weird glow was increasing. Jim stirred nervously.

"I don't mind telling you, I'm scared," he said.

"Aw, they won't make you walk back," consoled Clee; but he was scared himself. Why didn't something happen? Why didn't someone come out of the ship?

Jim thought he heard a noise, and touched Clee on the shoulder, pointing to a place on the trail down which they had come a few minutes before. Clee looked, and as he did so the hair on the back of his neck stood up. For the bushes along the side of the path were moving as if they were being brushed aside by someone in passing—someone making a straight line to the spot where they lay concealed. And no one was there!

"Can they be invisible?" breathed Jim, every pore in his body prickling.

* * * * *

For a moment the two men could hardly breathe, so great was their unnamed fear. During that time no other movements could be noted. Then Clee suddenly pointed to a bush only five yards away. Half a dozen leaf-tipped branches were bending slowly in their direction—and then a sharp crack, as of a broken twig, came to them from the same spot.

Panic, blind and unreasoning, swept them. "Run!" gasped Jim; and together, instinctively, they turned and scrambled down the side of the ridge to get away, anywhere, far from the approaching menace of they knew not what. Reckless of possible injury, they slid and stumbled down the brush-covered slope—and right behind them came sudden crashing sounds of pursuit.

New fears lent wings to their flight, but the sounds behind continued inexorably at their heels no matter how fast they ran or how lucky they were in making past obstacles. Their pursuer was as fast as they. They had no idea who—or what—it might be, for in the brief glances they snatched over their shoulders they could not see anything at all!

The going was bad, and the two campers had not gone more than a quarter-mile when they were breathing hard, and felt that they could not make one more step without collapsing on the ground to give their laboring lungs a chance to catch up. Panting like dogs they dragged themselves along through pine and birch trees, around large rocks and over briar-covered hills, only a few steps ahead of their pursuer.

Then Partridge, a little in the lead as they made their way up a steep slope, heard Jim suddenly go sprawling; heard him gasp:

"It's got me!"

* * * * *

Turning, he saw his partner rolling and threshing violently on the ground, and now and then lashing out at the empty air with his fists. Without a moment's hesitation he jumped from his position above—jumped square and hard into the space which Jim's invisible assailant should be occupying. With a great thud he crashed into some unseen body in the air, and went down, the breath knocked out of him. As he got to his knees an odor like that of cloves came to his nostrils, and something caught him around the neck and began constricting. Frantically he tried to tear himself loose, but the harder he struggled the more strangling became the grip on his neck; and at last, faint from the growing odor and the lack of air, his efforts dwindled into a spasmodic tightening and relaxing of the muscles.

Then, for a moment, the hold on his neck must have loosened, for he found himself able to breathe a little. Turning, he saw Jim at his side, apparently similarly held.

"If I could only—see it!" Clee managed to get out. Jim's spasmodic, bitter answer came a moment later.

"Being invisible—tremendous advantage!" he gasped.

In desperation the two men again began to fight against the clutches that were holding them, and this time the grip about their necks unexpectedly loosened—to bring to their noses the odor of cloves overpowering in strength. And that was all they knew before they lapsed into a black and bottomless void....

* * * * *

Through the lifting haze of returning consciousness Clee felt a command to get up. As he automatically complied he saw that Jim was doing likewise. Once on his feet he felt another impulse to go to the cherry-crystal sphere, visible in the distance; but his legs were weak, and neither he nor Jim could walk very well until out of the nothingness around them came something of invisible bulk to lend them support.

Slowly, carefully, straight for the waiting globe the two men were conducted; and in his state of half-consciousness Clee wondered at the impotence of his will to make his body offer resistance. They passed right by their tent and up the ramp to the inside of the strange sphere.

Clee's impressions were blurred and dull, but he noticed that they were in a small room brilliant with amber light, on one wall of which there was a circular area which contained a dozen or more instruments and levers and wheels. As his eyes rested on them, one of the levers moved, seemingly of itself, and the ramp came sliding into the ship and the thick door slowly swung closed. Then they were conducted along a short, narrow passageway into which opened, on the right, a small dim room; and there the grip about their bodies loosened and they slumped to the floor. The door whereby they had entered, closed.

A faint vibration became noticeable; they suddenly felt very heavy; and to the accompaniment of a low but rising hum they saw one wall of their room begin to glow with a beautiful cherry color. Although they had been too stupefied to try to speak, this spurred their tired bodies, and they dragged themselves over to it. They found the wall to be of some kind of hard crystal; it was the outer shell of the sphere; and it now gleamed redly transparent.

* * * * *

Far out and down the men saw a great convex surface on which lay narrow ribbons of silver, winding veinlike through dark areas that were in some places lit by little clusters of twinkling lights. As they watched, the distances on the surface shrank in on themselves; they could see the outline of a great circle. The sight stimulated the exhausted men. In a hushed and awestruck voice, Jim Wilson broke the silence.

"We've been kidnaped," he said. "Being taken God knows where, out among the stars...."

He was getting the sky-ride he had asked for.

Clee smiled faintly, and was going to remind him of this; but he was too tired to make the effort. He only looked at the tremendous scene below: at the Earth they knew so well, with its familiar streets, comfortable fireplaces, the faces of those they loved and those others who were their friends....

The Earth soon became a ball—a globe such as he had used at school, showing clearly the outline of the continents and oceans. And little by little it dwindled, until it was only a ghostly shape far out in nothingness....

A little later, had the two Earthlings not been deep in sleep, they might have seen enter a strange-looking man clad in odd garments—a man whose great, bulging head was quite bald, and whose wrinkled, leprous-white face wore an expression of unutterable wisdom and majesty. In his hands he carried a strange piece of apparatus which he held to Jim's wrist while it emitted a coarse vibratory hum that whined slowly up in pitch until it passed the range of hearing. He did the same thing to Clee, and then he quietly left.

But the two Earthlings knew nothing of this. Limp on the floor, oblivious to everything, they slept....

* * * * *

Some hours later found the kidnapped men well recovered and sitting on the floor of their cell talking over their situation. As usual, Wilson was thinking out loud.

"What can they be?—or who?" he asked, frowning with his thought. "They can't be from Earth, for no one there could invent such a ship as this and keep it a secret; and even if someone had, he could never have done the equally astounding thing of inventing a way to render living bodies invisible. I doubt if the thing that caught us was human, by what I was able to feel in my short struggle with it. There was something that might have been a hand; but the strength and the weight of its body was enormous!"

"Well, we'll probably soon see," commented Clee with philosophic resignation and pulling out of a hip pocket a package of tobacco and his corn-cob pipe. "Or, rather, we may soon know. Our captors may keep themselves invisible; and of course it's barely possible that it's their natural state to be invisible, so that we may never hope to see them. What I'm chiefly afraid of, is that they are from some other planet, and that that's where we are being taken—though heaven knows what any creatures so infinitely far ahead of us Earthlings scientifically could want with a pair of young Earth lawyers!"

He offered the package to Jim. "Here, have a smoke; you'll feel better," he said. "While there's tobacco there's hope."

"At least they don't seem disposed to kill us right off," returned Jim, handing back the tobacco after lighting his own pipe. "Later—if there's to be any 'later' for us—we may be able to find a way to get out of this room; though how we'd run the ship, to get back home, is another hard brick wall.... Maybe the controls are invisible, too!" he suggested with a wry grin. "Ever take any pre-law courses on how to work the invisible controls of a space ship?"

* * * * *

Clee's reply was spoken low, and was entirely irrelevant.

"That's funny," he said.

He was looking at the face of the watch on his left wrist. For the first time since they had been abducted, its abnormal brightness had left it.

As Jim watched, inquiringly, Clee moved his right hand a little, and once more the dial leaped out through the dimness with unnatural brilliance. Jim saw that his friend was holding in this hand the package of tobacco. Clee repeated the demonstration.

"The dial glows with unusual brightness always—except when I hold the package of tobacco in front of it at this spot," he said wonderingly, half to himself. "If I remember my science right, ultra-violet light would make the radium on the dial glow; and the lead in the tin-foil of the tobacco wrapping would screen it off. Let's see—"

He crossed to the other side of the room and held his watch and the package of tobacco in various positions until he again found one line along which the watch-dial gave off only its customary light.

"Yes," he said, "—exactly in the extended line made by my watch and this package of tobacco is the source of the ray which makes the watch-dial glow. It's probably the control room of this ship."

"An extraordinary deduction, my dear Sherlock," commented Wilson drily; "and valuable. I wish you'd now take a moment and deduce the reason for the mysterious appearance of the lumps on the back of our necks. I know I didn't have mine before I was taken for this sky-ride."

* * * * *

As he spoke, his hand sought the back of his neck where there was a fat lump about the size of a quarter—a lump not painful, for all its newness and size. Hard pushing with probing fingers had revealed something that seemed to be hard and flat, buried within; but close examinations failed to show any wound or scar, and the men had no notion what the lumps might be. Clee's was just like Jim's.

But Clee did not respond to his friend's invitation. A heavy mood had come over him; he was standing by the outer wall, looking out. Jim went and stood beside him, his hand on his shoulder, and together they gazed through the cherry-crystal wall of their prison ship out on the loneliness of the immeasurable miles outside. For them, space was red, instead of the deep black they knew they would see through colorless glass. Brilliant pinpoints of light, millions of them, in all sizes, made up the infinite space that was the background of their adventure.

To which one—near which one were they going? Would they ever return to their Earth again? Would their friends ever know of the incredible adventure that had overtaken them?—or would they, after the few weeks of searching and inquiry that must follow their disappearance, at last conclude that some nameless mountain disaster had made them victims, and give them up for dead? No doubt. And month after succeeding month their memory would fade from the minds of those who had loved them, while they would be—where?...

* * * * *

A peculiar, dynamic thought came simultaneously into the minds of the two men. It was not a word: it seemed more like a feeling; but its unquestionable import was "Come." Together they rose, and looked at each other wonderingly. Again came the feeling. They started for the door.

"But that's foolish!" Jim said aloud, as if objecting to his own thought. "The door's locked! We tried it!" He looked at Partridge, who returned his gaze blankly—and then, in spite of what he had said, he reached out and turned the latch.

The door swung open!

Expressions of surprise died on the men's lips as again came the compelling urge to go to some unknown destination.

"Suggestion!" said Clee, as he passed through the doorway. "Someone's suggesting—telepathically willing—that we come to him! And I—God help me—I can't resist!"

His neck corded with veins and muscles with his effort to restrain his body from obeying the mysterious command that was drawing it onward. Wilson, one arm outstretched in a repelling gesture, his legs stiff and tight, was also trying to resist. But the will that had sounded within them was stronger than theirs, and slowly, inevitably, they were drawn down the passage.

Their carpeted way took them back to the entrance chamber and then up a steeply sloping corridor that led upward to the left. As they passed along they saw that the hand of a master had made on the walls, in panel effect, marvelously complicated decorations in many-colored mosaic. No man of Earth could ever have done such work, the two men realized—and this thought did not cheer them any.

* * * * *

At the top of their curving passage a doorway led them into a spacious room hung with soft, finely woven tapestries with a metallic lustre and furnished with deep-napped rugs and luxurious chairs and divans. Through this room the intangible threads of the alien will directed them—on into a wide-vaulted alcove about one-third its size. There, the strange clutch on them relaxed, and they looked about, at first apprehensively, then with growing boldness and curiosity.

"This is the control room!" exclaimed Clee suddenly; and after a moment Jim agreed with him. It was the simplicity of the controls which had prevented them from recognizing it at first. Against the left wall was a great table with a tilted top, bearing, in its center, a raised and hooded eyepiece giving a view into a large, enclosed black box. On each side were several rows of small, shiny, metallic levers and what they took to be instrument dials—round, cup-shaped depressions with pointers free to move across dials lined with disorderly and meaningless convolutions. For the full length of the middle wall, straight ahead, was a broad table of some jet-black polished material, and on it was a large array of instruments and apparatus, all unfamiliar to them. Against the draperies of the wall to their right was one large cushioned chair, simple and beautiful in its lines.

No living person or thing could be discerned in either the main room or the alcove.

For several minutes the two men walked all about, examining everything they saw with curiosity and interest; and then Clee discovered a peculiar thing. His watch-dial, glowing very brightly now, would perceptibly increase in brilliance every time he neared the great chair. With sudden inspiration he took out his package of tobacco and held it in the line his watch made with the chair—and he found that his watch stopped glowing. He tried it again from another angle, and the result was the same. From that chair came the electrical disturbance that was making his watch-dial glow—yet nowhere near the chair was any bit of electrical apparatus to be seen.

What he did see in the chair, though, almost caused his heart to stop beating. The cushions of the seat, compressed before, began to puff out to full volume, as if someone had just risen from them. And then, faintly but sharply outlined in the long-napped rug in front, appeared the print of a human shoe!

"A man!" breathed Clee. "A human being!"

* * * * *

The two men stood frozen in their tracks. Clee's arm, with the package of tobacco in his hand, was still outstretched toward the great chair, but now the dial of his watch was glowing brightly again. Something within caused him in spite of his terror to move the package between the watch and the space above the footprint on the rug. The glowing stopped. The man—devil—whatever it was that made the print—was the source of the strange excitation!

This took but a second—the interval before another shoe-print formed in the rug in their direction. Jim gasped something unintelligible and started to back away; but no sooner did Partridge start to follow suit, than a compulsion to stand still came over them. Caught where they were, unable to move, they saw the shoe-prints come towards them. Slowly, step by step, twelve inches apart, they came, and did not stop until they were only four or five feet away.

"We'll jump him, if we get the chance!" hissed Jim, never taking his eyes off the prints.

"Yes," came the answer; but Clee's further words were cut off in the making by an added compulsion to keep quiet. Were their words understood? The two men were locked, speechless, where they stood. And by some creature with a human footprint whom they could not see!

The touch of firm flesh came out of the nothingness of space about them, to poke and pry all over their bodies. Anger began to take the place of their fear, as, for some time, impotent of resistance, they had to submit to the examination given them. They were prodded and felt like dogs at a show; their breathing and heart action were carefully listened to; their mouths were opened and their teeth inspected as if they were horses offered for sale. Both men were inwardly fuming.

"Dogs!" shouted Clee in his thoughts. "Treating us like dogs, to see how healthy we are! Does he want us for slaves?"

* * * * *

At last the examination came to a stop, and they saw the shoe-prints in the rug go over to the black table and remain there, heels toward them, while various pieces of apparatus were invisibly moved across the table top. For a moment the compelling will did not seem, to Clee, to be constraining him as much is it had, and he began to wonder if he might not have a little control over his body again. Tentatively he tried to break through the oppressing blanket of foreign will; his arms and legs moved a little; he succeeded! He caught Jim's eye and showed him. He thrilled all over at his discovery, and his will to move measurably increased with his growing confidence that he could.

The toes of the prints were still turned away. He was going to try and get the man or monster who was making them.

He gestured to Jim, and with a great effort took a step in the invisible man's direction. A thrill of gladness helped him on—for Jim was following suit!

Again and again, with greatest mental effort, they made steps toward the footprints, which, remaining side by side and motionless, gave them increasing hope of stealing up unobserved. When they were only three feet away Clee motioned to Jim, and with a tremendous effort of will they jumped at the space where their enemy should be.

They hit him hard, and bore him heavily to the floor. By the feel, he was a man such as they! Clee's blood leaped with the lust for revenge, and blanking his mind against strong urges to cease his attack he rained savage blows at the place he was holding.

But almost at once they had evidence that their opponent was not such a man as they. A terrific pain stabbed suddenly through them, and they doubled up on the floor, writhing in agony. It was as if every nerve in their bodies had turned into white-hot wire, and was searing through their flesh. Again and again came the terrible stabs of pain—and their source seemed to be the mysterious lumps at the back of their necks!

* * * * *

At last they ceased coming, and Jim and Clee stretched out on the floor all but unconscious from the terrific shocks of fiery agony. They were completely helpless; further thoughts of resistance were unthinkable. But they were not left lying long. There came a telepathic compulsion to stand up; and they found themselves obeying, in spite of the shrieking protest of their every nerve.

Twitching, stumbling, they were made to do servile things—to kneel on the floor; get up again; turn round and round; bow low, then stretch backwards. And out of the air around them came shocking blows which landed on their faces, necks and chests; feet which kicked out at their shins; and they had to stand there and take it, helpless to resist.

Then Clee, as the nearer of the two men, was pushed over to the work-table, where an oval head-piece of finely-woven wire was fitted over his head. Another very large one, standing next to it, and connected to it by wires which led to a small instrument panel nearby, lifted into the air until it must have settled about the head of their persecutor. A dial on the panel turned slowly. And gradually the helmet resting in the air dissolved into nothingness before their eyes.

A slight nausea swept over Clee as it did so, and in the midst of it he felt a series of sharp, staccato thoughts—thoughts which did not seem to be composed of words, and yet were clear and intelligible.

* * * * *

"Fool of a fool!" crackled in his brain with almost a physical effort, "do you think to resist Xantra? Do you think with your sub-human minds to overcome one of the Tillas, Masters of the Universe? Close you were to death—and death indeed would have come had I not other plans for you.

"Know that henceforth you and your companion are my slaves. You will jump at my slightest will; serve me as best you can with such intelligence as you may possess. For faithful, willing service you shall have food and clothing and a portion of leisure. Disobedience and tardiness will bring you the pain you have already tasted; revolt, or the attempt to escape—death; but only after torture such as you have never known.

"I shall never repeat this mode of communication: it is as physically nauseating to me as to you. And you may never expect to see me, though I can always see you. By vibrational means I have given you the universal atomic rhythm of all Tillian slaves; and, although in that state your fellow-slaves will be visible to you, I, your master, will not!

"You will now return to your place of confinement. After you have recovered you will be taken in hand by your fellow-slaves and shown your duties. And if your instinct for self-preservation is only one-tenth normal, you will never again be such a stupid sub-animal fool as to attempt to resist Xantra—to fly in the face of the inevitable!"

The sharp, staccato voice in Clee's brain stopped; his nausea began to leave him; his helmet was removed; and had he been looking he might have seen the other one slowly materialize on the table. The ordeal was over just in time, for the last remnants of his strength was giving out—as was Jim's. The two Earth-men slumped down, and would have fallen but for the telepathic will, stronger than theirs, that forced them erect again. There came a very strong compulsion to return to their cell, and bruised, stumbling, their nerves still afire from their strange stabbing pains, they made their way back.

They fell to the floor and passed into unconsciousness—beaten, subdued. Slaves....

* * * * *

After a long blank interval a distinct thought crossed Clee's mind. He was in heaven, and an angel voice had spoken. There it was again! Cool hands were stroking his wrists and forehead. He opened his eyes and looked, but seeing no one closed them again.

The Voice returned, and two of the words which kept repeating were somehow familiar. "So sorry ... so sorry...." The Voice was low and cool and feminine. And someone was bathing his battered head.... He rolled over and got up on one elbow. He still could see no one.

The Voice said: "Oh, I'm so glad you're better! I thought you'd never come to!"

Mechanically Clee asked: "Who are you?"

"Vivian Gray," came the quick answer; "from Boston. And you?"

Clee did not answer, but started to lie back again. Things were all wrong: he couldn't even see anyone. He'd go back to sleep, and wake up some other time. But the Voice wouldn't let him.

"Oh, you must listen!" it said. "I haven't much time!"

"Where are you?" he asked.

"Why—right here!" came the surprised answer. "Can't you see me?"

"No," answered Clee, still not himself. He added categorically: "I can see Jim. I can see the door. I can see my hands, but I can't see you."

"Oh, then it must be true! Xantra told me he was going to make you one of his common slaves; but I hoped—I hoped—"

* * * * *

This didn't mean much to Clee; but with the words came memory of all that had happened, and with sudden concern he crept over to where Jim was lying, to see how he was. He found him blinking and stirring, aroused by the voices. Quickly he explained the invisible presence to him, warning him to be on guard.

"Oh, but I'm a friend—Vivian Gray—kidnapped from Earth just like you!" came quick explanation out of the air. "Xantra stole me from Cape Cod, where I was vacationing, about the time he took you. Xantra is the one whose space ship we are on. He looks much like a man; he is some kind of a man; but he's not from Earth—"

"You've seen him?" interrupted Clee, beginning to believe the Voice a little.

"Yes," came the instant response; "not when he abducted me—he had made himself invisible for that—but always after. Haven't you yet?" And then, without waiting for his answer, she gave it herself. "But of course you couldn't see him if he's already given you the universal atomic rhythm the slaves have. You'd then be able to see only each other, and the other slaves; not Xantra and not me.

"I think he makes his slaves that way for protection," she explained. "They can't very well plot or rebel against him when they can't even see him, and never know but what he's around."

"Who are these slaves you keep mentioning?" Jim broke in. "How many of them are there on this ship: and how many like Xantra?"

* * * * *

"Xantra is the only one of his kind," came the answer. "The slaves are a race of inferior people found on his planet—wherever that is: I couldn't understand, from his explanation, just where. They are creatures much like ugly human beings with a touch of the ape, and are entirely bald, very strong and not very intelligent. There're seven or eight on board. Normally they are good-natured: but sometimes when they have a hard master, like Xantra, they take to hating him; and when they do that they can be very fierce and treacherous. That's the main reason for Xantra's stopping at Earth: to see what kind of slaves we humans will make. He is hoping that we will be more intelligent than those he has—and more docile, and safer to have around."

"Well," snorted Jim belligerently, "if Mr. Xantra thinks that I'm going to be safe to have around, he's a lot dumber than I am!"

"Oh, it's good to hear you talk that way," the girl's voice went on. "We three have got to stick together, and find some way to escape!

"I've so much to say!" she went on; "but I daren't stay long, for fear of getting caught. What you said is where my chief hope lies: Xantra doesn't realize how intelligent we are, and how dangerous; and we mustn't let him know! I think he believes we are much like his present slaves: he gets away with murder with them. You've noticed the lumps on the back of your necks? Well, they have them, too; it's something that's attached to the spinal cord and gives him telepathic control over them; also the power to hurt them dreadfully—as you've unfortunately found out. His slaves don't understand these lumps; they don't seem to know that he would lose control if they could only in some way get rid of the things in their necks!"

* * * * *

For the first time since the girl started talking, Clee spoke. His voice was low and grave, and there was a tinge of suspicion in it.

"Just how does it happen," he asked, "that you know so much about things here?"

The girl's voice broke as she gave her answer.

"I'm ashamed to tell you," she said. "Xantra—he—he admires me as a healthy animal; one close, in species, to himself. He thinks by being nice to me that he might be able to make me a willing companion to share his trip!" For a moment the girl was silent; and when she spoke again there was a hard note in her voice.

"I let him have hopes," she said, "—deliberately. I planned to make him trust me, and give me the run of the ship, so I could find out all I could. So far—before you came—I saw no slightest hope of ever escaping back to Earth; but I had at least to look for a quick, sure way to death, in case—in case—"

"You—and us too!" exclaimed Clee impulsively. "No Earth-man—no American, at least—is ever going to submit to slavery. If the worst comes to the worst, we'll at least die together, Vivian!"

Jim added soberly: "And perhaps, if we do, no one from Xantra's planet will ever again come to Earth looking for 'docile' slaves...."

* * * * *

For a moment everyone was silent, affected by the thought behind what they had said. Then the girl's voice suggested, with a touch of Earth formality that was almost ludicrous under the circumstances: "But you two men have not yet introduced yourselves!"

Both Clee and Jim smiled, and told her their names, and in the slight pause that followed Clee said awkwardly, almost shyly: "Miss Gray, we don't know what's in store for us here, and it—it's possible that we may never know each other any better: so would you—I mean, I wonder would you mind if I reached out and touched you. In spite of all we have said. I—I can hardly realize that you are there, somewhere, before me."

Out of the nothingness came an impulsive soft hand that closed over his. There was both a smile and something deeper in Vivian's voice as she said, "Here," and raised his hand until it touched her brow and the thick smooth hair of her head. Then she placed it a little lower, over her face; and gently Clee's fingers told him what his eyes could not read.

"In case you never see me—why, I—I'd like you to know that I'm really, not bad looking," she said; and Clee knew she was blushing as he smiled at the eternal feminine in her.

* * * * *

But the smile suddenly left his face. His hand had felt her give a distinct start. Then—

"He's calling!" she gasped faintly. "Xantra's calling for me to come to him!" Her voice, as she spoke, moved, and Clee knew she was going towards the door.

"No!" he cried impulsively. "Don't risk it! Stay here, and we'll begin our fight against him right now!"

"I will be safe," came Vivian's reassuring voice from the door. "I can manage him a while yet." Her further words came with a rush. "But I wanted to tell you—I had a faint plan. If I could get hold of the anaesthetic—the vial of stuff that smells like cloves—"

The door was closing now, and the two men knew she was moving down the corridor. They listened in vain for her to complete what she had been saying. Just before the door clicked shut, Jim jammed his foot in it, preventing it from closing.

"Gee, that girl has courage!" Clee murmured.

For a moment the two men looked at each other. Jim was thinking about the opened door, and the chance they had to get out. But Clee's mind was on something else.

"Well, Jim," he said, "you and I have a nasty job ahead."

Jim looked at Clee wonderingly as he took out his pipe and stuck it in the crack of the door, allowing him to remove his foot. Clee explained to him what Xantra had told him with the thought-sending helmets; reminded him of what they had learned from Vivian about the lumps on their necks. After he had finished he said quietly but decisively:

"Now, we're going to try and remove whatever is under these lumps. Have you got anything sharp? Your knife? Something with an edge on it?"

It would mean escape from the domination of Xantra's will!—from his terrible stabbing punishment!—if they could remove them! Jim breathed a little quicker in his excitement.

"But once we do it—if we can do it—it'll mean that we'll have to make our break to escape right away," he reminded Clee. "We'll be caught if Xantra wills us to come to him and we don't appear!"

"You know what will happen to Vivian if we delay the attempt." Clee reminded him levelly: and Jim knew that Clee was right—that their break for freedom must start right then and there....

* * * * *

He looked through his pockets and produced some cigarettes, matches, a pipe, a nailfile and some utterly useless odds and ends. Clee's hands came out of his pockets empty. "I've got nothing at all," he said—and picked up the nailfile and looked at it questioningly. "We'll have to use this, I guess.... Well, I'm first."

He lay face down on the floor and loosened his collar. Quietly, he made several suggestions. "Light a match and heat the tip in the flame," he said. "The point's pretty dull, but cut as deep and quick and clean as you can. If I yell, pay no attention; I'll try to hold still. Unless it bleeds very much, best not make a bandage; we've nothing clean enough."

That was all he said; and Jim, his heart beating like mad, and a lump in his throat, could find no words at all. He sterilized the tip of the file as directed, studied the lump a moment, then, after a rough, affectionate shake of his friend's shoulder, he knelt close to his task. One quick hard cut; a sharp gasp from Clee; a repetition; then two more times crossways—and a firm, spongelike metallic disc lay revealed. Then the worst—raising it a little, and breaking the several fine wires that led from it through the flesh within....

Clee lay panting, the sweat running down the deep wrinkles of pain on his face. Dark blood oozed from the jagged wound. But he smiled a little, and some of the pain-wrinkles in his face smoothed away, when Jim showed him the disk....

For a short time Clee rested, quieting his nerves, while Jim staunched the flow of blood.

And then it was Jim's turn; and he bore the sharp agony as stoically as Clee....

It was perhaps a strange thing; but at this great moment in the lives of the two men they felt no need to talk. For the few minutes they rested after they had done, no word was spoken; but in that time a bond of friendship was formed that only death could ever break....

* * * * *

They did not rest long. Every moment brought them nearer to the inevitable discovery of what they had done. Their muscles were still quivering, the wounds on their necks still slowly bleeding, when Clee rose and aroused Jim. The most dangerous, desperate part of their wild revolt lay just ahead.

They were able to make but the vaguest of plans, not knowing what to anticipate outside. They only knew that they would first have to strike boldly for possession of the control alcove—which, without doubt meant they would have, somehow, to kill Xantra—to find and kill a man they could not see, yet who could see them. An enormous task. And only the first of several.

For a moment, realizing this, they hesitated at the door. But the die had been cast; there was nothing for them to do but go forward—and quickly; so, giving Jim a final warning that they must stick together, Clee opened wide the door and stepped out into the corridor.

What he saw there halted, him in his tracks.

"The slaves!" gasped Jim, and involuntarily both Earth-men backed into the room again. The creatures they had seen at once followed them inside.

There were four of them. As tall as men, they were, and the general cast of their bodies was identical. But they were different in shocking little details. Their heads were much larger, and in the shape of inverted pears, like those of hydrocephalics; their eyes, popped and dull. The thin lips beneath their stubs of noses were ever writhing and twisting in horrible grimaces. And, worst, their skins were sickly-white, and were absolutely bald of hair. The only clothes they wore were loin-cloths and very large sandals, which exposed to full view their chunky, muscular bodies.

All this the two men took in at a glance. They knew they could never hope to cope, unarmed, with four such creatures as these, so they stood with their backs to the wall, alertly awaiting their first move.

"Easy," warned Clee. "They're probably only coming to take us in hand, as Vivian said."

* * * * *

The nearest of the slaves stepped a little closer to the two men, and by the twitching of its eyelids and the increased mouthings of its lips it was apparent that the creature was highly excited. A high, variable moaning sound came from its throat. Curiously, boldly, it looked Clee all over—and then it did an amazing thing. Seeing the blood on the back of his neck, it swung him around, put its writhing lips to the still-bleeding wound and dog-like licked it clean.

The gesture was altogether a friendly one.

Another of the slaves of Xantra went up and did the same to Jim, and the two men looked at each other with relief. This meant that the removal of the disks had not been understood by the creatures!

It was with growing hope that they allowed themselves to be conducted from their cell, through the sloping corridor into a doorway they had passed coming in, and down a curving flight of steps into a large room below. They were in the space at the very bottom of the ship, for, through the redly-glowing transparent walls that curved on each side and below, they could see the infinite deeps of star-filled space. Three other slaves were there, waiting for them. At the far side of the room their guide pointed to two small stalls, with a partition between, which they understood were to be their beds. They were across from a long row of similar ones.

"Making us right at home," commented Jim. "I wonder if they'll serve cakes and tea."

"Wish they would," added Clee; "I'm getting damned hungry. But we've got work to do—and we've got to do it quick!"

His eyes swept the room, looking among the sparse furnishings for something they might be able to use as a weapon. He saw nothing, but the sight of the lump on the neck of a nearby slave gave him an idea.

"I wonder if these slaves would fight for us if we removed the lumps from their necks," he said musingly, his eyes narrow. "I wish there were some way to talk to them...."

* * * * *

He looked from one to another of the animal-men making a circle about them, wondering what to do; then quickly he made his decision. "Jim, I'm going to try. It'll have to be done by signs; I've got to make them understand, and get their permission."

At once he raised his hand to get the slaves' attention; then, raising both fists high in the air, he shook them violently, at the same time gritting his teeth, working his face, and growling in animal anger at something overhead. He was trying to show the slaves his anger at Xantra, above.

The slaves fell away from him in surprise and alarm, not understanding what he was trying to put across. He continued his demonstration, hopping about furiously, but still without result. Then Jim cried out:

"Touch the place on your neck!"

Clee did so, and the result was startling. Quickly there ran around the circle throaty growls of anger, and every slave raised a hand to the lump on its neck. Evidently they had all felt the awful punishment-pain of their master.

Heartened by this, Clee extended his pantomime. Stopping his demonstration of anger, he put one finger on the wound on his neck and fell to the floor, writhing in simulated pain. As he lay there groaning, the easily aroused animal-men moaned with him in sympathy. Then Jim, inspired, stepped into the act. Taking out his nailfile, he bent over the prostrate Clee and pretended to cut into his neck, making a great show of removing something and throwing it away; and as he did so Clee jumped to his feet and grinned and hopped about the room in a wildly exaggerated affectation of joy and relief. Then he stopped his acting and carefully showed the slaves the wounds in his and Jim's necks, by finger movements doing his best to make it clear that they had removed something from there.

And then, taking no chances, he repeated the whole pantomime, Jim, at the proper place, acting his part as before.

* * * * *

When at last he stopped and looked around, he was over-joyed at his apparent success in putting across the idea. All over the room the animal-men were repeating his show in its various phases.

"Now I've got to take the disk out of one of them," said Clee, "and it's a mighty dangerous thing to attempt! You see how easily their emotions are aroused. If I hurt too much—!"

"I know," responded Jim, "but we've got to risk it, for if we succeed we've got a good bunch of tough fighters at our backs. We need every bit of help we can get!"

Carefully they made their few preparations, and Clee, again by acting, indicated to one of the animal-men what he wanted to do. He seemed to make himself well understood, for without hesitation the creature lay face down on the floor. The others all gathered around as Clee bent over it, and Jim scanned their faces closely for any sign of suspicion or resentment. Seeing none, he told Clee to start; then held his breath in awful suspense.

The disk appeared near the surface, and with a quick slice Clee made his first incision. With the cut, the prone slave bucked and snarled. Clee murmured soothing words to it in English, and, as the creature quieted down, made another cut. Again came the bucking and throaty protest; and this time, to Jim's dismay, he saw in the bestial faces of the animal-men around them a sympathetic swing of emotional protest. A little more, now; and Clee would be able to take the disk out; but would the slaves restrain themselves until then?

Again Clee allowed the brute body under him to calm down. Then, as he was about to cut once more, from somewhere above in the space ship came the piercing scream of a woman. Something was happening to Vivian.

* * * * *

Clee half started to rise, to run to her aid, but he forced himself to be reasonable. Weaponless, visible, he could never hope to rescue an invisible girl from someone he couldn't even see. He was on the point of making valuable allies; in just a few moments more—! He decided to hurry through with the job he had undertaken.

All below had heard the scream. The circle around him was shifting uncertainly, and peculiar sounds were coming out of the brutes' twisting mouths as he bent again over their fellow on the floor.

Clee's hand was trembling like an aspen leaf as he prepared to make the next incision. He was completely unnerved, and with the utmost efforts of his will he was unable to control the nailfile. And he had to hurry!

He sliced as straight as he could at the bleeding lump; the slave moved; and the point of the file slipped deep into the creature's flesh!

At that, with a snarling growl the brute below arched from the floor and flung Clee sprawling. From all around the circle came menacing growls as the bleeding animal-man lumbered to its feet and came after him in a definite attack. Jim, not at that moment the center of their attention, pushed one of the slaves in the way of the charging brute and the two of them half fell; and before they could recover their balance Clee was on his feet making after Jim to the steps that led up out of the room.

"Up!" came Jim's shout. "Fast! We've made them enemies!"

Above them on the stairs was descending another slave, innocent of what had transpired below, and the two men bowled it over in their haste to get past. All the way to the bottom of the stairs it tumbled; and that delayed pursuit for the moment needed by the Earth-men to gain the upper corridor. Quickly they darted through the door; there was no way they could lock or block it, so they had to run on. Taking to the left, they found themselves in the little entrance room, and from there their only course led up the corridor leading to Xantra's quarters and the control alcove.

Arrived there, the two men found the door ajar, but they paused irresolute before it, hardly daring to go in. They had no choice, however, for behind, only fifteen feet away, came the van of the animal-men. They pushed through the door, closed and bolted it, then, wheeling tigerishly, surveyed the room.

* * * * *

They saw no one.

They were not relieved at this. Xantra might well be there; he, as well as Vivian, would be invisible to them. And he had every opportunity of striking first; even then he might be preparing to deal with them, if he was in the room. The slaves were not attempting to break in the door to get them—and this was ominous: it argued that the master was there.

The two men stood motionless at the door, peering intently at the rug in search of telltale footprints. Then Clee touched Jim's shoulder and whispered faintly in his ear:

"Cloves! Smell it?"

Jim nodded. Slowly, on guard every second, they advanced to the alcove. They saw no sign of anyone there, though the odor of cloves was stronger. Jim grabbed a chair and held it ready, and Clee followed suit with a small, heavy tabouret. Cautiously, methodically, the two men began to reconnoitre the large room, examining foot by foot the rug in search of the faint clear prints that would reveal the presence of their enemy. The smell of cloves was beginning to dull their brains a little. Clee saw the danger in this, and whispered to Jim:

"Faster! Xantra may be insidiously anaesthetizing us! We've got to find where he is—quick!"

They hastened their search, feeling more and more sure that Xantra was close by. And not till then did Clee remember that he had a way to discover Xantra's location. Jim heard him curse under his breath; saw him put down the tabouret and take out his tobacco; and knew at once what he was about to do. He went close to Clee, to guard him with his chair against possible attack.

* * * * *

The face of Clee's wrist watch was glowing brightly; it took only a second to find with the package of tobacco a spot which cut the dial's unnatural glow. As they found it the skin on the two men's bodies prickled all over. The line from the dial to the package of tobacco, if continued, would reach a spot on the floor not six feet away. And looking carefully there they could barely make out, in the bent hairs of the rug, a broken outline that might have been made by a prone figure.

As they prepared to jump they heard from that place a low sigh—and just before them appeared the distinct print of a human hand. Xantra was rising! And coincident with this a sudden banging at the door told them that the slaves at last had started to break in!

As one man the two Earthlings leaped on Xantra; he would have to be taken care of first. When they had fastened on his rising body they punched and pounded it furiously. Though their enemy was undoubtedly only half conscious, the sudden attack aroused him and he resisted vigorously. But then Clee made a lucky connection on what he felt to be his jaw, and the invisible form in their arms went limp.

"Get a rope—wire—anything to bind him with—quick!" yelled Clee. "I'll hold him!"

The pounding at the door was increasing ominously is Jim dashed over to the work-table. Rapidly he looked for something suitable, and in a few seconds was back with a length of stout wire which they quickly wrapped around the ankles and wrists of the limp form Clee was holding. As the wire touched Xantra it gradually disappeared from their sight, but their fingers reassured them that he was tightly bound.

Then they were at the door, which, shivering and bending from the battering without, showed signs of giving in. With herculean efforts they dragged a heavy divan over and wedged it tightly against it; then added other furniture in a tight supporting pile. But the door, of some light metal, was not built to stand such a siege, and was buckling further inward with each blow being dealt it. More and more plainly the two men could hear the triumphant snarls and howls of the animal-men.

Frantically they ransacked the rooms looking for what they thought might be weapons, but found none. They looked at each other with dismay. It was only a question of time—minutes—before the slaves would break in. What could they do?

* * * * *

In that tense moment of indecision a low, weak voice reached their ears—a woman's voice, and one they remembered well.

"Vivian!" cried Clee, and ran to the alcove, from whence it had seemed to come. The girl's next words brought them understanding.

"Clee—Jim—it's Xantra! He's willing the slaves to break in! He's lying bound on the floor, but he's conscious!"

Clee ran to where he had left the invisible man, cursing himself under his breath for being an utter ass for not having guessed this. His groping fingers quickly found the squirming Xantra's neck; and he had begun to throttle him into unconsciousness when Vivian called out:

"No! Don't! That won't stop the slaves: they've already been given the order! We've got to make Xantra stop them! Here—drag him to the work-table! I've got something—"

Wondering what the girl was about, Clee relaxed his grip on the invisible man's neck and complied. But he suddenly understood—and Jim, too—when he saw coming through the air the pair of thought-sending helmets. He had a way of communicating with Xantra, of course! He saw the larger helmet lower to rest over the head he was still holding; then soft hands placed the other over his own.

As it settled down a great crash sounded in the other room: the door had given in. It was still held almost in place by the tightly-wedged furniture, but that would not hold the animal-men long.

"Hurry!" cried Jim. "I'll stand by the door!" And he was already on his way to it.

Clee saw the small panel on the table above; saw the knob on it turn. He caught Vivian's excited voice. "Tell him to order them to stop," she said; "or else—or else—"

"He dies!" finished Clee, viciously thumbing into the air where the invisible Xantra's neck was.

* * * * *

With all the intensity he could muster, Clee concentrated on one simple, strong thought. He hardly heard the triumphant cries of the slaves as they felt the blocking furniture give before their efforts; all his energy was being expended in the will to get his thought across.

"Tell those slaves to stop breaking in or you die!" he commanded.

The noises at the door continued. Either Xantra had not understood, or else he was stubborn. He repeated his command and threat, and still the crashing sounds came to his ears.

Desperate, he played his last card; and unconsciously his lips formed the words of his next mental command, so that it was understood by the breathlessly watching Vivian.

"Tell them to stop!" he willed. "No more air till you do!" And with the words his fingers closed tightly over the other's throat.

The sounds at the door continued; for a moment the invisible form between Clee's knees writhed violently—and then suddenly, almost magically, a silence fell over the whole room. Clee had forced his will on Xantra! He had made him stop the slaves!

And just in time.

Clee's fingers relaxed a little on the throat of the man beneath him. He turned and said: "Quick, Vivian—find that anaesthetic!" A moment later it was pressed in his hands. "Say when," he told the girl, and held it beneath the nose of the helpless man. Xantra's head at once fell back, and he heard Vivian telling him to stop. He pulled away the bottle, corked it and stood up.

"Well, that's that," he said.

* * * * *

For a moment he was silent. Only the noises made by Jim in strengthening the barricade at the door could be heard in the room. Then he said, earnestly:

"I wish I could see you, Vivian—right now; but that'll have to wait. I guess...."

A low laugh came from the place where the girl was standing. A hand touched his arm, and he found himself being conducted into the alcove. Vivian laughed again; said, teasingly, "What a stupid expression on your face!" then commanded him to shut his eyes, and keep them shut. He felt something being attached to his wrists; heard a coarse hum that quickly rose in pitch until it passed the range of hearing. He was caught up in a surprising exhilaration; he heard the hum again, sliding down and down in pitch, while every atom in his body felt a sickening vibration that grew ever coarser. Then suddenly he felt normal; the things on his wrists were removed and Vivian told him he could open his eyes.

He did so. He had guessed what she had done, but he was surprised, nevertheless, to see the straight, slender, attractive girl who stood before him.

"You see, Xantra used this on me twice—the latter time to restore me, so I would be able to see him. I watched him carefully," the girl explained.

Clee gazed at Vivian in greatest confusion. Why—she was beautiful! He grew conscious of a growing need to say something, and eventually the asinine thing that left his lips was:

"Yes—you—you aren't bad looking at all."

The girl turned away, blushing; and it was Jim who relieved Clee from his awkward situation. He came swinging happily through the alcove portal to suddenly stop in blank surprise. Clee had disappeared!