DREAD-FLAME OF M'TONAK

Ketrik came in from Perlac, came fast, using the Frequency Tuner all the way. Now his great bulk came forward in the control-seat, his eyes fastened intently on the dark blue disk of Earth that loomed ahead.

"Strange," he muttered. "Strange, no Patrollers! I expected an escort at least, if not a challenge!"

But no one heard. Ketrik, as always, had come alone. The helio from Mark Travers, recorded on the sensitized receivers at Perlac, had been more than a summons and a plea; it had contained an undertone of urgency. Ketrik had left at once, making the trip from the newly discovered outer planet in record time, thanks to the secret power-unit which the Earth Council still coveted.

Ketrik thought of that now, as he neared Earth where he had not set foot for so long. He remembered the tedious negotiations between Earth and Perlac, designed to bring the latter planet into the Solar Federation—a status hardly equitable to the Perlac government, due to Earth's high-handed demands. For Earth still claimed priority on Brownell's "Frequency Tuner," despite the fact that he had been forced to flee with his invention to Perlac; and since then there had been an alarming exodus of Earth's scientists to Perlac where they could work out their ideas unhampered.[1]

The Earth Council remained haughty, adamant. Only six months ago there had been a skirmish beyond Jupiter in which several Earth Patrollers had gone to flaming destruction against the speedy Perlac ships. The "Perlac Incident" was developing into open, bitter warfare. Venus remained wisely aloof, riding a crest of peace under the reign of Princess Aladdian. And on Mars, Dar Vaajo sat brooding on his ancient throne, silent and watchful.

"Maybe I'm being a fool," Ketrik murmured now as he crossed the orbit of Earth's moon. "Mark Travers guaranteed me safe landing and full protection—nevertheless—"

Weary but still cautious, he switched to the auxiliary rocket-power, then went to work dismantling the Frequency Tuner. In a short time he had jumbled the unit into a confusion of its component parts, and carefully hid it away. He trusted Mark Travers ... but there were others.

As he picked up the grav-beam for his landing, he thought again of Mark. It would be good to see him again after four years. He wondered if the lad's status as "Member of Council" had changed him any. Even more, he wondered at Mark's urgent message.

The city spread below. Then the landing field. Ketrik berthed with practiced ease, stepped down from the lock.

The guards closed in fast. There were dozens of them. Ketrik had only time to glimpse the black-and-silver insignia of the elite Council Guard, the drawn guns and grim purpose on their faces. Even as he whirled back toward his ship, the deadly song of a heat-beam sounded past his ear—so close he could feel the swirling scorch of it.

Ketrik came erect and motionless. He turned slowly, brain wry with the thought that he'd come into a trap after all. But he smiled—a twisted smile which failed to erase the hard lines of his face. His eyes were a puzzle, gray and serene but somehow mocking beneath the dark bangs tumbling across his forehead.

The Guards formed a watchful circle about this man whose deeds were renowned throughout the System. For a moment their Captain hesitated. Then, squaring his shoulders, he stepped forward. His gun became intimate with Ketrik's wishbone.

"George Ketrik, I arrest you by order of the Supreme Earth Council! You will come along peaceably or suffer the consequences!" The man's voice was overly loud, arrogant. With a dramatic gesture he removed Ketrik's gun, then whirled him into the hands of the Guards. They marched toward a waiting tube-car. Other guards were trying to keep back the crowd, passengers for the Venus Express who thronged the field.

Ketrik's eyes were emotionless now, devoid of color. He said tonelessly: "Taking quite a chance, aren't you, Captain? I've only counted fifty of your men."

"We've heard too much about you, Ketrik! And we want you alive—that's why we didn't try to take you in space. I'm glad you're being sensible about this."

Ketrik shrugged his towering shoulders as though to say, "Why not?" But his mind raced. So they wanted him alive. They were nearing the tube-car now, and the crowd, eternally curious, was trying to press in.

It was now or never. Ketrik stumbled. His elbow shot back, caught the captain in the stomach. With the same motion he snatched the latter's heat-gun, and bending low, lunged to the left. The crowd parted before his onrush. Women screamed at sight of the gun he waved before him.

Ketrik heard shouts and curses from the startled guard, but he knew they wouldn't fire into the crowd. A uniformed man loomed before him, swinging a gun-fist up. Ketrik was quicker. The guard went down from a sledge-hammer blow. Grinning joyously, Ketrik evaded two others. He twisted and turned through the crowd, with some notion of gaining the tube-car and escaping into the heart of the city.

And it might have worked. Now a path was opening clear. But this time he really stumbled, lost his balance momentarily. It was enough to allow the guards to close in. Ketrik twisted erect, felt clutching hands upon him and heard the bellowing voice of the captain. He swung out with his arms, felt men flung backward. He tried to bring up the heat-gun.

This time someone else was quicker.

A heavy weight crashed against Ketrik's head, a sun exploded into millions of fragments which dwindled away as he plunged forward into darkness.

He regained his faculties quickly. His subconsciousness demanded it. This curious "awareness" in which Ketrik had trained himself had saved him from many a tight scrape.

But now he did not open his eyes at once. He knew he was in the tube-car, for he could feel the cushioned seat beneath him and the faint vibration of the gyro-motors. Then he became aware of another fact.

He was alone.

This brought him to his feet, wide-eyed and alert. He felt the weight of his own gun again in his belt, examined it, found it still loaded. Strange!

Where were the guards? Why should they be sending him somewhere alone? A glance at the crystyte window revealed a flashing panorama of the city. He knew he was moving at terrific speed, probably on a special "right-of-way." To attempt an escape now would be suicide.

He shrugged, settled down in the seat. His capture had been well planned, but he failed to see what the Council hoped to gain by it! Ketrik felt a surge of cold fury at this treachery—a treachery in which Mark Travers must have had a hand.

Presently a braking signal flashed green. The tiny car sighed, as though exhausted from its headlong route across the city. It came to a stop against the forward cushion of air, and doors of duraplon slid smoothly back.

Hand near his gun, Ketrik emerged into a long empty corridor of black and silver. Black marble walls reached sheerly up, to curve away into a filigreed ceiling. Priceless tapestries adorned the walls, caught a hidden overhead glow and shattered it into lances of silver radiance. Ketrik frowned, looking at these tapestries. Their design was interwoven with thousands of Kra plumes, those priceless silvery plumes for which he'd risked his life many times among the wild peaks of Ganymede. Only the very elect could afford them. He knew now, that he must be in Earth's Council Chambers.

Again he felt a tingling awareness, knew that unseen eyes were upon him. He straightened his shoulders and walked unhurriedly toward a massive door at the end of the corridor. As he neared it, there came a tiny click and the door slid back.

It was a large room but startlingly bare. A huge table of Martian majagua wood, with a dozen surrounding chairs, occupied the center. The only other article was a magnificent Ethero-Magnum, with screen reaching nearly to the ceiling—an instrument powerful enough for communication with Venus, Mars, even the Callistan colonies.

To Ketrik's surprise, only one Member of Council was present. This man had risen as Ketrik entered. Ketrik stared and it took him fully a minute to recognize this man. It had been four years since he had last seen him, out there at Perlac—but now Mark Travers seemed to have aged twenty years!

Mark came slowly around the table, hand thrust out in greeting.

Ketrik's voice was like a whiplash.

"Nice going, Travers! I trusted you, so I came right into your little trap! What is it you want—the Frequency Tuner? Or am I just plain under arrest?"

Mark stopped in his tracks. A pained look swept across his features. Ketrik went on mercilessly.

"And I expected a better reception than this! Where's the rest of the Council? I'll save you time, though, and tell you that Perlac has ceased negotiating. We're prepared to fight for our independence and free enterprise in the System!"

"I know that, Ketrik. I'll continue to champion Perlac's cause against all odds here!" Grim-faced, Mark began pacing the room. "As for the other eleven Council Members—they don't even know that you've arrived on Earth. I'm risking my position in Council, perhaps my very life, by bringing an outsider into these chambers without a quorum present!"

Ketrik's mien underwent a change. "You mean I'm not under arrest?"

Mark laughed. "Of course you're not! That little show at the spaceport was faked, had to be. And," he smiled a little, "thanks for adding the touch of realism. Moreover, your spacer is in safe hands."

"Well, son, congratulations!" Ketrik grinned broadly. "You sure had me fooled. But what about the rest of the Council, if they learn that I'm on Earth—"

"By the time they do, it won't matter. You won't be here." Mark stopped his pacing, turned to the famed adventurer. "Ketrik, I sent for you because I need you desperately! Earth needs you! I have reason to believe that Earth is facing the greatest danger in its history."

"Earth." The bronzed exile spoke the word quietly, but with a world of contempt.

"Well, then, the entire System! Even Perlac. I believe it will strike first at Earth, in fact may already have done so."

"And this danger. Danger from what?"

"Ketrik, you'll probably think me a fool—but I don't know! It's so damned vague it's terrifying. I do have an accumulation of data that points to Mars. I want you to go there."

"Mars? A second-rate power. Their race is dying out, and their science goes with it."

Mark shook his head. "Don't underrate Dar Vaajo! He's an old man now, but cunning. An opportunist. He's never forgotten how Princess Aladdian of Venus, through her treaty with Earth, put an end to his dreams of conquest."[2]

"Yes, I remember it well." Ketrik was thoughtful. "But how could Dar Vaajo make a play now against the power of Earth, or for that matter Perlac?"

Mark permitted himself a smile. He didn't miss the implication that Perlac, too, was fast becoming a power to be reckoned with.

"I'll give you the facts," he said quietly, "and you can judge. About two years ago, Dar Vaajo stopped all Uranium shipments from Mars. That in itself is comparatively unimportant. What is important, is the Earth Council. Now consider, Ketrik—I've been close to these men for four years. Very often it has seemed to me that where rudimentary logic should dictate a course of action, they incomprehensibly choose to follow another. So it was with this Uranium embargo. They might easily have forced a showdown, but instead, they seemed satisfied with Dar Vaajo's peculiar evasions.

"Of course, about this time Earth's quarrel with Perlac was reaching a crisis. But even there, I noticed definite trends of irrational thinking on the part of the Members. At our frequent sessions to discuss the Perlac question, they seemed to appreciate all the factors involved—even that we were fast losing our best scientific talent to Perlac. Yet their damned egotisms crept through, dictating to their reason. Ketrik, I swear to you that when they voted sending a fleet of Patrollers out to Jupiter to prevent your men from landing there, I did everything in my power to prevent it. But again my voice was one against eleven. And believe me, the majority vote of Council is final—irrevocable."

"I have reason to know that," Ketrik said. "But, Mark, I still fail to see this danger you spoke of."

"I'm getting to it. And this is the part that's frightening. About a month ago, in my own home, I set up a secret Cerebro-Scanner. Know what that is?"

"Never heard of it."

"It's new, and plenty dangerous in the wrong hands. Works on a ray principle. Produces elaborate graphs of an individual's mental and emotional co-ordinates. Well, on a secret wave-length I probed the minds of my fellow Council Members!" Mark smiled. "Yes, I'd probably receive sentence of death if they knew, but the end justified the means. Ketrik, the resulting graphs reveal that the cerebro-thalamic co-ordinates of the Council Members do not vary in the slightest! They are the same down to ten decimal points!"

Ketrik gestured helplessly. "Is this important?"

Mark stared at him. "Important—it's unprecedented! Much the same as finding eleven identical sets of fingerprints! But what is worse, the graphs show elements of—of—it's hard to explain. Certainly not disloyalty! Rather the opposite. An intense loyalty, but governed by unreason. Their minds seem directed along a single channel, toward a definite end. And that is—the utter humbling of Perlac! Nothing else seems to matter!"

Ketrik nodded. Then he asked the obvious question.

"Did you employ this Scanner on yourself?"

"To make the record complete—yes! Needless to say, this tenacity of purpose concerning Perlac is utterly missing from my own mental co-ordinates."

"Hmm. How do you account for that?"

"I can't. But this mental trend in the others seems to be induced. Now, you begin to see the implications?"

Ketrik nodded slowly. "Yes, son, and you're right! It even begins to scare me a little. Suppose Dar Vaajo in some way has gained control of those eleven minds—is that what you mean? But why Dar Vaajo?"

"There's one more item that completes the pattern, and points to Mars. During the past year, as many as four of our spacers have disappeared on the Earth-Mars route. No trace has ever been found. However, about a month ago, a life-boat from the missing Terra III was found drifting near the orbit of our moon. Aboard was one survivor—Dr. Curt Ransome, the brilliant physicist and mathematician, returning from a lecture tour on Mars."

"And could you learn nothing from him?"

"No." Mark's voice was tragic. "We learned nothing, because—his brilliant mind was gone! The doctors say it's doubtful if he'll ever respond to treatment. He babbles incessantly, has the mind of a week-old infant!"

Ketrik was aghast. "What has the Council done?"

"Nothing, of course!" Mark laughed bitterly. "They're pre-occupied with Perlac! I've personally contacted Dar Vaajo on the Ethero-Magnum. He expresses regret and puzzlement, offers every aid in tracing the disappearing ships. But there's an under-current of evasion. As a desperate measure I sent two secret operatives to Mars."

"Good," Ketrik nodded his approval. "They get through all right?"

"Yes, apparently just in time. Dar Vaajo has thrown a close guard about the planet. Anyway, my operatives managed to set up a communications base in the wilds of the K'Mari Range, half a day's flight from Turibek, capital of South Mars. I've contacted them twice. They report strange activities at Turibek, something in the nature of a vast scientific experiment! And another thing. Dar Vaajo apparently has made a truce with the Rajecs."

"The Rajecs! Those Martian Outlanders?" Ketrik's face was dark with real concern. This news seemed to affect him more than anything Mark had said.

"We've really never learned much about those strange desert tribes," Mark went on. "But—"

"It's impossible!" Ketrik said. "Those Outlanders hate the Upper Martians with a hatred beyond our understanding. Nothing would impel them to make truce, absolutely nothing! I know, for I once lived among them for six months." Ketrik was as near to being excited as was possible for him. "Yes, Mark, I'll go to Mars. This really begins to interest me!"

II

They spent much of that night in going over their plans. Ketrik had no misapprehensions about landing on Mars; he could do that despite Vaajo's patrols. Turibek presented the real problem.

Carefully he perused the tele-strip recordings from Mark's operatives, E-39 and EV-5. There had only been two reports, and they were brief.

"This last one was sent two weeks ago," Mark said, "and I haven't been able to contact them since. The channel's dead. I'm afraid it means their hide-out was discovered!"

Ketrik studied the rough map Mark had made, showing the location of the hide-out in the K'Mari Range, and its position from Turibek.

"This will help. I'll try to get over there, see if anything's left of their sending equipment. Then I want to make a try for the city. If I can get inside of Turibek, and maybe get a line on this scientific thing they're working up ... I was at Turibek eight years ago, and know it fairly well."

"Here's a photo-static air view," Mark said. "Afraid it doesn't show much."

"It shows one thing," Ketrik said, studying the film. "Dar Vaajo's had a wall built completely around the city. That wasn't there eight years ago! And those towers stationed around the wall—what do you suppose they are?"

"Control towers. That's an electronic wall! And you'll observe there's another within the city itself, surrounding that group of buildings which must be the laboratories. Ketrik—if you ever get in there...." His voice dwindled away in doubt.

"You don't think I can do it? I don't either, Mark—not as an Earthman!"

"Come. We'll fix that."

They passed through endless corridors, arrived finally at a large white-enameled room. It was complete with operating tables, instruments, plastics, ray-lamps—everything necessary to Earth's espionage system.

Ketrik stripped piecemeal, allowed every inch of his superbly muscled body to be subjected to the stinging Ulmo lamps. Gradually under the hot rays, the very pigmentation of his skin changed to the deep reddish-copper of a Martian. Mark proved himself an expert at this. Even the insides of Ketrik's ears did not escape the ray.

"Don't worry," Mark told him. "This will all wear off eventually."

"Yes? How long?"

"In about two years! Now, your eyes. You never saw a Martian with gray eyes. Look up just a moment."

A few drops of liquid, a harmless vegetable composition, changed Ketrik's eyes to a muddy golden color.

"Those bangs have got to come off!" Mark went to work in earnest. Ten minutes under another ray, and Ketrik's unruly hair was transformed into tight, crisp curls in keeping with the Martian fashion. His features presented the hardest problem, but Mark worked miracles with the plastics and equipment.

At last the job was done. When Ketrik surveyed himself in the mirror he saw a tall, somewhat arrogant Martian of the middle class, with slightly flaring nostrils, bulging cheek-bones and lips curving in a thin, cruel smile. He nodded, more than satisfied.

Mark consulted his wrist-chrono. "Four hours until dawn. Better grab a few hours' sleep, it may be your last for a while."

"Sure, but I'll rest better if I know one thing. Where's my ship?"

"My guards moved it secretly to the underground repair locks. Right now it's undergoing as radical a change as I just performed on you." Mark smiled. "When you leave Earth, it will be in a slow-powered ore freighter ostensibly bound for the Moon!"

An hour before the dawn, Mark wakened Ketrik. But Mark hadn't been idle in those hours. He handed the other a small, compact instrument.

"Here's a Scanner disc I just finished assembling. It only works within a very short range, but you may have need of it."

They took the swift tube-car across the city and arrived at the spaceport amidst surprising activity. A Callistan freighter had just berthed. Bright lights were trained upon it, men and trucks were moving about handling the cargo.

"I planned it for this hour," Mark explained, "because now less attention will be drawn to you. We can't be too careful." He pointed to a dark, far corner of the field where a clumsy bulk rested. "Believe it or not, that's your ship. The exterior's been changed but that's all. You still have the Frequency Tuner." They paused for a moment in solemn thought. "I can't impress upon you too much, Ketrik, what this—"

"That's right, Mark, you can't. So let's not mention it." Ketrik was brusque. "Believe me, son, I know what I'm up against."

"Send any news at all as to what Dar Vaajo's up to. If I learn that, I can rouse the people of Earth to preparedness in spite of the Council." He thrust out his hand. "I'll say goodby now—and good luck!"

Ketrik said simply, "You'll be hearing from me, Mark." He moved across the field, keeping to the shadows, the collar of his space tunic turned up. He wondered how many of the men working about this field were Martian "Specials." Some of them, surely. If he, an Earthman, could be molded into Martian guise, Dar Vaajo could certainly perform the same miracle in reverse and probably had.

He reached his ship undetected. All was dark and quiet. The hull, he noticed, had been painted solid black. He entered and flicked on the lights. Mark was right, nothing on the inside had been changed.

He explored the ship to make sure. Then he moved forward to the control-console, remembering that this was supposed to be a clumsy Moon freighter. The rockets roared. The ship moved with slow acceleration up the step locks, to finally catapult into the stratosphere.

And five minutes later, just as he was clearing Earth's gravity, he heard the voice behind him:

"Well, Ketrik, at last! Really—I thought you were never going to make it!"

Ketrik had long since learned caution in these matters. He turned slowly now and was glad he did. The first thing he saw was the gun—a powerful weapon, an electro. The fist wrapped around it looked firm and experienced. Ketrik's gaze went to the man's face.

It was the Captain of the Guard, the same captain who had met him at his landing eight hours before. The man was cold-eyed now. He kept a few paces away from Ketrik.

Ketrik said, "I searched the ship. Where were you?"

"You failed to look in the emergency fuel locker. It was a tight squeeze for me." He smiled tightly, surveying Ketrik's transformed figure. "A nice job. Slightly tall for a Martian but, withal very nice. Too bad all that ingenuity has to be wasted at the very outset."

Ketrik's muscles tightened. As though it were a signal, the other's voice became brittle.

"Up! Up with those hands, Ketrik. I have a few questions to ask, and then—"

It seemed ridiculously easy, the way Ketrik did it. He let his eyes go dull. He sighed and raised his hands, slowly. He saw the other's gun-fist relax ever so slightly. Then Ketrik's legs gave way and he went swiftly downward. The captain fired but Ketrik wasn't there, his powerful muscles had launched him forward, beneath the hissing beam. His shoulder caught the other just below the midriff and bent him double, carried him backward. They crashed into the controlroom door. Ketrik's left hand found the other's gun-wrist and twisted powerfully. A bone snapped, the electro skidded away. The captain began a curse but it was cut short by Ketrik's right hand at his throat.

Ketrik pulled the man to a sitting posture. He gazed deep into the eyes which were glazing over with pain. But it was not enough to prevent the true color from shining through ... the color of dull, tarnished gold.

"I thought so," Ketrik murmured, and then his hand loosened, balled into a fist that drove forward. The man laid back and went limp.

Ketrik's fingers probed the other's face. The man was a Martian, all right, the features had been subtly altered. Enough to fool even Mark! Captain of the elite guard! How long had the man masqueraded in that position, Ketrik wondered—and then he shrugged. It didn't matter now.

He went through the man's clothes, found nothing of interest until he came under the left arm-pit. There, next to the skin, he found a tiny metal disk. He rose, went over to the wall-light to examine his find. The disk was perforated with queer Martian characters. Ketrik knew Martian, but he couldn't quite make these out. He bent closer.

A sixth sense warned him, or perhaps it was some slight sound. He whirled. The Martian's hand had moved, was now grasping the electro which he swung up into line. Ketrik's hand dropped and he fired his own heat-beam from the hip. The beam cut a clean swath across the other's chest, and he died without so much as a sigh.

"Sorry, buddy, whoever you are," Ketrik whispered. "Guess I'd have had to do that anyway, though. When Dar Vaajo plants Specials like you on Earth, we don't play for fun!"

He fastened the identification disk under his own arm-pit. Five minutes later, from the starboard lock, he dumped the body into space and without a qualm, rayed it to dust.

Then, champing with impatience, Ketrik allowed his "freighter" to plod Moonward. He skirted within five thousand miles of it, then with the satellite as a shield between him and Earth, he charted for Mars.

His brush with the Martian operative had sobered him. He began to realize that Mark had every reason for alarm! The subtle tampering with the Council's mental patterns, the placing of operatives in high Earth positions, the secret scientific experiments on Mars—they all had to tie in. He was sure of one thing now. Dar Vaajo, an embittered old man, was making one last bid which would bring his race to its former glory or else carry it forever to extinction with him.

There were surely other Martian operatives on Earth, and they would have established a communications base. By this time they had undoubtedly flashed the news of his coming. Ketrik smiled inwardly. Very well—they'd be expecting him at Turibek, but he'd take the indirect approach.

All the way to Mars his mind was at work. He was remembering days he'd spent in that wild desert country of South Mars. From the tide of his thoughts he segregated events ... places and people ... the canals and cruel deserts, the customs of the Rajecs, those fierce black outcasts from the cities of Mars. He knew that before he got through to Turibek, he'd need all this. Already a plan was forming....

Twenty hours later he sighted a Mars patrol, six formidable spacers athwart the Earth-route. They moved leisurely, in perfect formation, and Ketrik knew their network of "finder beams" covered a large area. However, the power-principle of the Frequency Tuner defied those "finders." No challenge came through his open radio, which meant they hadn't sighted him yet.

A solid black ship was strictly against the Space Code, but Codes mattered little now! With the ebony backdrop of space behind him, Ketrik's ship would be hard to detect. He decided to try a sneak past them. He'd have to go into Inferior-plane, but he was sure he could make it.

Quickly he changed course, swept into a sharp parabola that carried him far below the Ecliptic. In a matter of minutes he was watching the Mars-cruisers fade away into darkness. His present course would bring him far over into Mars' dark-side, but that was what he wanted anyway.

Hours later the vast South Desert was rising up below him. Deimos had just appeared, climbing with slow majesty across the sky; Phobos would come a few hours later, pursuing its reckless course. Ketrik peered far ahead to the horizon. There, against the dark downward curve, he saw a faint glow that was not the glow of Deimos. He knew that must be the capital city, Turibek, untold miles away. He made swift calculation. To the right, then, would be the K'Mari Range. He knew those mountains. It would be the very place to leave his ship.

He dropped lower and headed for there. The pale ghost-glow of Deimos didn't help much. He switched to infra-red, peered at the V-Panel as it lighted up and saw the unmistakable, serrated line of mountains about twenty miles away. He had judged it that close! Ketrik grinned proudly.

It was short-lived. A Martian voice sliced through the radio, shrill and commanding.

"Ground! You, below there—you will ground immediately or we blast!"

Then Ketrik realized that for the past several minutes there had been a faint humming sound from above and all about him, scarcely heard. He had relaxed in his vigilance, and the Martian 'copters had picked out his trail—those fast-powered and deadly scouting ships. They too must be equipped with infra-red!

Even as these thoughts raced through his mind, Ketrik was acting. He leaped away from the V-Panel, grabbed the Control and threw it over. Too late now! The ship responded, but sluggishly. The nose veered sharply upward, trying to leap away—then the entire hull shuddered. Power-beams! It must be a vast concentration of them, to stop Frequency power! Slowly his forward progress was retarded. Relentlessly he was being forced down into the Martian sands. Again the voice sliced through.

"It is useless, outlaw! We've had you in our finder for the past five minutes and you are in a network of Power-beams. Nullify your control immediately or we blast!"

Ketrik cursed. Already his ship was straining at the seams. And now he felt insufferable heat all about him, realized they were using the beams. His stomach turned over as he thought of his rocket-tubes loaded with fuel....

Quickly he entered the starboard lock; stood peering down. He was dropping fast. Above him now he saw hosts of vague shapes, heard the whine of Martian 'copter blades cutting the air. The metal under his fingers was growing hot. He counted to five, slowly ... and leaped outward.

It may have been thirty feet—or fifty. Ketrik only knew that he was plummeting downward. He let his muscles go limp, and just in time. He hit the sand hard, rolled over once and knew that no bones were broken. Above him he saw the pale glow of heat-beams, saw the hull of his spacer growing cherry-red ... and suddenly realized his danger.

He staggered up, went ploughing across the desert, still mentally counting off the seconds ... "eight ... nine ... ten...." The explosion lighted the sky for a hell-filled moment. Ketrik went hurling forward, to land head foremost into the sand. Parts of his ship came thudding down about him.

One fragment, red-hot, landed against his arm and burned it severely. Other fragments scattered over a wide area. Ketrik was cursing now, unconsciously using the mono-syllabic Martian in which he had versed himself.

Then it was all over. Ketrik was glad of only one thing. His ship was gone, but the Frequency Tuner had gone with it! The Martians would never get that priceless power unit. He rolled to his back and looked up.

It was not over! A few 'copters were descending to view the wreckage—or perhaps to look for him. Had they seen him jump? Powerful searchlights began criss-crossing the area. Again he staggered up, went forward into darkness. Every muscle ached, but his eyes were alert for the beams. Whenever one passed near him, he flattened into the sand. After untold agonies, he judged that he was fairly safe. Far behind, he heard the drift of excited Martian voices.

He didn't rest. He kept going away from those voices. They might still be looking for him. He was utterly confused in his direction now. He could be going toward Turibek, or toward K'Mari Range ... or out into the vast wilderness to the south. One of those dark storms was sweeping up, and Deimos was hidden. Soon the sharp sand began to pelt him.

Ketrik turned up his collar and ploughed on. He remembered that those storms usually, but not always, came up from the south. He guided his direction by that, and plunged on.

"At least one thing's settled," he muttered after a while. "I'm relieved of the problem of hiding my ship!"

III

Through adventures on every far-flung world, every barren satellite, Ketrik's uncanny "time-awareness" had never failed him. It didn't now. He knew that it was precisely one hour and twenty minutes later when he saw the flickering lights, so he couldn't have come far. He saw the lights but once, quite a distance ahead and low against the ground. Then they were gone as the sand rose in renewed fury.

He moved cautiously now. He didn't see the lights again but knew he was going toward them. Ketrik was no stranger to this south desert. Now the old nameless awareness was with him. It may not have been anything he heard—but he suddenly knew that very close, just beyond the radius of his vision, unknown shapes moved through murky darkness. The very sands seemed to whisper the danger. But Ketrik heard other sounds now. The sounds he heard were sibilant footsteps and they were patient, very patient, as they kept pace with him.

He became suddenly motionless, held his ears attuned. The soft footsteps stopped, but not before Ketrik determined that they were on both sides of him now and probably behind him as well. He nodded grimly and went on, no longer trying to tread softly. He loosened the electro in his belt. These might be Rajecs or they might be the scavenger rats that trailed a man until he dropped. In either event....

He knew very soon. They came hurtling out of darkness at him, great black shapes, silent and swift. But they were man-size, which meant they were Rajecs. His electro was out, but he didn't get a chance to use it. A muscular hand seized his arm and bore it painfully backward. Other Rajecs crowded in. Even at this close range Ketrik could see little except their eyes, feral as flaming topaz.

Even Ketrik could not fight that which he could not see. But he tried, tried grimly until the weight of their bodies bore him down. He remembered that these people could see in darkness. They undoubtedly saw that he was "Martian," and his life would be forfeit unless....

He was trying to remember something else, something out of Rajec legendry. A single word. It came to him then, and he ceased fighting. He whispered the word fiercely.

"S'Relah!"

It was magic. The clutching hands loosened. He could feel the black muscular figures draw back, hesitant.

"You are Martian!" one of them hissed.

"But S'Relah, I tell you!" Ketrik spat the word. "I am one of you!"

They helped him to rise, but kept firm grip on his arms. "We will see. Come."

They went forward through darkness. Presently they were mounting a slight rise. From the top of it Ketrik looked down at the campfires of a Rajec caravan, a large one.

As they moved down the slope, Ketrik realized he'd have to stick to his word. His mind raced, building up a brief but, he hoped, suitable story. He was sufficiently versed in Martian history. He knew that aeons ago vast tribes of these black-skinned Rajecs had been dominant on the planet. But the "Upper Martians," so called, had progressed phenomenally. They were superior in the arts, social government, science, and the "culture" of warfare. They had swept down from the north, expanding, building their cities and developing their waterways, the now famous Canals. A bitter thousand-years' war had driven the Rajecs ever southward into the merciless deserts.

There they had stayed, waging periodic but futile warfare. Wild and tribal now, they still had never forgotten. The S'Relah was a fanatic, inter-tribal society ... persisting through countless generations, dedicated to a relentless hate of those upper Martians. And Ketrik knew what few men knew—that among the S'Relah were many renegade Martians, outlaws and embittered "politicals" usually, working through the Society for personal gain or revenge.

Ketrik had his story ready as they came into the camp. The Rajec leader was sent for. This man was large, well proportioned, the muscles beneath his ebon skin high-lighted in the glow of the central fire. He was armed merely with a razor-edged dagger in a jewelled belt. Ketrik, looking at him, felt respect and a certain foreboding—the latter occasioned by the slight enigmatic smile about the other's lips.

The man eyed Ketrik with equal interest. His keen gaze lingered overly long on his "Martian" features. He certainly noted the electro which Ketrik retained, but it didn't seem to bother him. He spoke at last, in Martian.

"You claim to be S'Relah. We will need proof of that. What is your name?"

"Khosan."

"Ah, yes. Khosan. And where do you come from?"

"L'Ottli." Ketrik named a small mining camp far to the south. "Been prospecting there for six months, trying to make stake enough to get up to Turibek."

"Yes. We, too, go to Turibek. You knew that?"

Ketrik allowed puzzlement to show in his eyes. The other went on. "You seem surprised, Khosan. Had you not heard, then, that your emperor, Dar Vaajo, has signed a treaty with the consolidated tribes of Rajec?"

"I had not heard. And I believe you lie! The Rajecs would never make treaty!" Ketrik hoped his disbelief sounded convincing.

"It is true," the black shrugged. "But that does not matter. Your going to Turibek matters. A foolhardy thing to attempt alone!" The enigmatic smile still lingered. "But, then, being at L'Ottli for so long, you were not aware of Dar Vaajo's scouts everywhere. This area has become thick with their 'copters—especially in the last few hours!" There was calculated meaning in the last words.

Ketrik decided on a bold stroke. He said calmly, "Yes. I am aware of it now. They blasted my plane out of the sky scarcely an hour ago. Perhaps you saw that?"

"We all have observed a slight display in the sky to the west. You know—Khosan—word reaches us swiftly and in many ways. It is rumored that Vaajo's scouts are seeking to apprehend one who may come here from Earth." The black paused, but Ketrik's eyes never flickered. "They may even search this area. They know our camp is here. There should be a reward of many Martian credits for capture of the one they seek!"

Ketrik shrugged. "That explains why they fired at me. I guess they mistook me for that one."

The Rajec's smile vanished abruptly. His next questions came fast. "You are S'Relah? Why are you S'Relah?"

"Political. Irreconcilable. My father was a 'political' before me."

"Where do you go in Turibek?"

"Where the Street of the Double Moon makes juncture with the Low Canal is a tiny shop dealing in curios from the far planets. The proprietor is one Jal Thurlo. I go there for a meeting with him."

"And the reason? The reason—quickly!"

Ketrik's gaze leveled and he said slowly, "You would not expect me to tell you that. He too is a 'political'."

"You can quote the oath of the S'Relah?"

Ketrik had been waiting for that one. Now, in a low voice, he quoted the oath which not all Rajecs, very few Martians, and probably no Earthman save himself had ever heard. It was a strange and terrible oath, an oath hallowed in blood, and its implications would have made some men blanch. But Ketrik spoke it feelingly. He finished the words and looked closely at the black's face.

The man was satisfied and strangely moved, albeit slightly puzzled. He drew a tremulous breath at last.

"You have proven! You may go on to Turibek with us. We travel afoot and the way is slow, but certain."

"That is agreeable."

The leader drew Ketrik aside, out of hearing of the others. "At the rear of our caravan is a small group of Martians, prospectors from the nearby mountains—a ragged, harmless lot, whom we tolerate. I think it advisable that you travel with them. Dar Vaajo's Specials are stationed along our route."

Ketrik nodded curtly, started to move away. The Rajec stopped him. "This mining camp you mention, this L'Ottli where you have been for six months. Is it not far, far to the south, at the extreme end of the K'Mari Range?"

"That's the place." Ketrik was on his guard.

"I thought you would like to know there is no L'Ottli. That entire town was wiped out in a great avalanche three years ago. Oh, yes, one more thing." The black was smiling now, looking at the place on Ketrik's arm where the hot chunk of metal had burned the sleeve away. "That is a bad burn, and a strange one—for a Martian."

Ketrik looked at his injured arm for the first time. Around the area of the burn was a tiny outline of white—the white skin of an Earthman showing through. Only the keen eyes of this Rajec would have noticed it.

"I'll give you other garments," the man said. "You had better burn these. Good night, and sleep well—Khosan."

But Ketrik didn't sleep well. He burned his garments and donned the others, then found the camp of the Martian prospectors. There were six of them, all asleep now. Ketrik found a place by the fire and lay awake, speculating.

The Rajec leader he trusted. The man was undoubtedly of the S'Relah. But these six Martians would be suspicious of him, a newcomer. If they hadn't yet heard of the search for a spy in the area, they would certainly hear of it on the morrow! And they'd report him to any of Dar Vaajo's "Specials" they met along the line of march.

That last thought gave Ketrik his answer, a temporary one at least.

At dawn the caravan moved. The six Martians were surprised at this newcomer, but not yet suspicious. Ketrik didn't give them time to be. From beneath his arm-pit he produced the thin disk which he'd taken from the slain Martian operative. He flashed it briefly, asked a few curt questions, and the men were properly cowed. Apparently they knew the power of Vaajo's Specials.

"Just routine," Ketrik told them. "I'll travel along with you for a while." Determined to play his role to the hilt, he added, "We can't be too careful in these times. There may be S'Relah among these damned Rajecs, but we'll find them out before we get to Turibek. Dar Vaajo has gone too far in his plans to have them thwarted now."

By tactful conversation he sought to learn something of what was going on at Turibek. It soon became apparent that these bedraggled men didn't know, and cared less. One of them had heard of Dar Vaajo coming to Turibek with a complete staff of scientists, but that's as far as his knowledge went. Another of the men had heard of the treaty, and wasn't surprised.

"I've seen it coming," he said gruffly. "Many years I've lived in these deserts, and I tell you the Rajecs aren't the same. Especially the last few years. Something just seems to have gone out of them."

Something indeed had gone out of the Rajecs, if they made treaty! Ketrik wondered what kind of magic Dar Vaajo had used to bring that about. More particularly, why! There was some sort of link here, between the Rajecs and whatever was going on at Turibek. And that, in turn, was a pivot in Vaajo's larger plan, the plan that would deal with Earth. Ketrik just couldn't piece it together as yet; he'd have to get to Turibek. He thought fleetingly of those electronic walls....

The sun climbed higher, hot and dry, sapping the strength. Ketrik marvelled at the long line of marching Rajecs—there were perhaps two hundred. Long years in these deserts had inured them to discomfort. Again he wondered why they were going to Turibek. Almost he was tempted to go up and speak again with the Rajec leader—the man's name was Aarnto, he learned—but he thought better of it.

At high noon they stopped for rations, and a few hours later the Martian 'copters came over. They came from the direction of the city, circled once, and flew leisurely back. Ketrik wondered what that meant. He was soon to know.

Presently Aarnto dropped back, fell into step beside him and drew him away from the others. "You saw the 'copters?"

"Yes," Ketrik replied. "Trouble ahead?"

"For you, perhaps, O mysterious one from out of the desert! Those 'copters mean there is a surveying station ahead, and the Specials will be there. Apparently they are still searching for the spy."

"These surveying stations—what do they do there?"

"Oh, they are diabolic, these Specials of Vaajo's! They have machines which tear a man's mind apart, probe into his inner thoughts. No spy could ever get past them."

"Then how do you propose to get by, O grinning one?"

The black continued to grin. "True," he said frankly, "I am S'Relah. And there are several others among us. We shall get by the Specials all right, and into Turibek by the main gate. For the past year we have prepared for this, through systematic thought-control. We can submerge our true thoughts so that all the machines will read will be obeisance and loyalty."

"Seems ticklish," Ketrik said. "But I guess I'll try that too." He had no intention of trying it. He was watching Aarnto's reaction.

"Listen to me." Aarnto was serious, gripping Ketrik's arm. "You could never manage it. It takes months to perfect such mind control, and you have only hours. I do not know why you wish to get to Turibek, but you quoted the oath to me. I know of another way into the city for you—it will be perilous but not so perilous as trying to run the gauntlet of Specials!"

"I am listening, O helpful one."

"We will reach this station before sundown. If you should leave the caravan now, and cut across desert to the foothills, you would be safe. Once over there...."

Now it was Ketrik who grinned. "I know. Once over there, I might find the entrance to the ancient South Canal."

Aarnto was amazed. "You know of that too?"

"I've heard of it, but don't know the exact location."

Aarnto pointed to the K'Mari Range, indicating twin peaks that curled up like devil's horns. "Guide your course directly between those. The Canal ends somewhere in the foothills below."

"Thanks, Aarnto." Ketrik placed his hand on the man's shoulder, in the Rajec custom. "May I repay you some day!"

"That day may come soon," the other said calmly. "I can almost promise it."

Ketrik wondered what he meant by that, but wasted no more time on words. Turning abruptly, he set out across the desert. The six Martians watched him go. One of them, who had been silent and surly, frowned thoughtfully now as he stared after Ketrik's retreating figure.

Ketrik judged the hills to be fifteen miles away at this point. He'd be lucky if he reached them before nightfall. After that, well, there were tales about those abandoned Canals....

He directed his course between the curving peaks. In a few hours the ground began to rise slightly, became firmer underfoot. Still later, deep little gullies began crossing the terrain. He followed these, changing from one to the other, searching for some sign of the Canal.

After an interminable search, he was rewarded. He began to notice peculiarities of the gully in which he trod. It seemed to level out, and the walls seemed smoother and higher. He scraped away layers of sand, saw ancient stone.

By this time the sun had dropped below his vision. He knew that any minute the Martian night would come with awful suddenness. And with it, would come ... other things.

But Ketrik was unprepared for what came in that moment. He heard a sudden sharp whirr of blades, and a 'copter appeared above him! It swept so low he could almost see the pilot. There was no doubt the pilot had seen him, for a heat-beam sliced downward, swept along the Canal floor. Ketrik leaped aside, hugged the sandy wall.

Then the 'copter was gone, but Ketrik knew it would circle and return. That could only mean one thing. The caravan had reached the Station, and one of those Martians had spoken of him to the Specials.

Ahead, through the gloom, the Canal seemed to dip into a sort of culvert. He raced for it as he heard the whirring blades again, entered the dark tunnel just as the heat-beam sprayed downward, sending the sand into molten froth. Ketrik groped forward in darkness. The tunnel leveled and continued. Ketrik's heart leaped as he realized where he was. This was one of the abandoned Canals which had been filled with slag from the Martian mines. But years ago pirates had conceived the unique idea of burrowing through it, making a perfect retreat from Turibek to the mountains!

Suddenly he started. Far behind he heard a scuffle of steps. That could only be the Martian Special! There was no doubt, now, that word had gone to Dar Vaajo; they really wanted to stop him! Ketrik grinned and went on, hurrying his steps a little. Rajecs could see in the dark, but Martians couldn't. If it came to a showdown....

His grin soon vanished. All about him now he heard vicious little animal squeals, the scuffing of tiny feet. Scavengers! There must be thousands of them. He saw their baleful red eyes. They gradually grew bolder, began nipping at him. Soon his trousers were in shreds from the knees down, and he felt the flow of blood.

There was one satisfaction. The Martian coming behind must be suffering the same treatment! But the man kept coming. The footsteps were dogged and Ketrik knew he had a real antagonist here.

Now the scavengers were becoming more than annoying. He knew that before he ever reached the city, he would weaken from loss of blood and they'd pull him down. He could use the electro to clear a path through the vicious beasts—but he knew the one coming behind was waiting for that, waiting for any sign of light that would give him a clear target. Ketrik gritted his teeth and went on, occasionally kicking out at the beasts in the dark. It didn't do much good.

Then, far ahead, he saw the faintest glow of light. It seemed to come from around a bend in the tunnel. If he could only get up there in time—and beyond that light, before his pursuer came into view....

He sprinted ahead now, noiselessly. The scavengers squealed in renewed fury, racing along beside him. Once he stumbled, felt a horrid mass of the things swarming. But he fought his way up. By the time he reached the light, he was sure he had gained a considerable distance on his pursuer.

He hurried around the bend, saw that the faint light came from a radium lamp in the ceiling. It had probably been there for years. But what held his attention, and brought him to a standstill, was the figure huddling against the wall.

It was an Earthman and he was still alive. His clothes were in shreds and the rats had been at him—before he reached this light where the rats did not come. He struggled up weakly, gazed at Ketrik out of idiotic eyes. Ketrik hurried forward, pulled the man erect.

One look into his gibbering face, and Ketrik felt his stomach turn over in a prodigious yawn.

It had taken more than the rats and darkness to do this! The Earthman's mind had been literally and deliberately blasted!

Ketrik suddenly remembered what Mark had said of Dr. Ransome, whom they'd found drifting near the moon ... his mind that of a week-old infant....

He hurriedly searched the man's clothes, but found nothing. He knew this must be one of the operatives whom Mark had sent a month before—E-39 or EV-5. The other must be dead, somewhere in this tunnel or back at their communications base in the mountains.

He spoke softly to the man, but the other only cringed in terror. Then, with unexpected strength, he tore himself from Ketrik's grasp and was scuttling away, back around the bend of the corridor. Ketrik followed, called a warning. He reached the bend too late. He heard the hiss of a heat-gun and saw the vivid blue streak of it from out of the darkness—a streak that touched the Earthman's chest and sent him crumpling.

Ketrik fired at the spot where the ray had appeared, fired instinctively but unerringly. He heard a soft moan that ended abruptly, then a clatter of sound.

He moved slowly forward, hugging the wall. He feared a trick. Past the little radius of light where the Earthman's body lay, he stumbled upon the Martian Special. He flashed his electro again and saw that the man was unmistakably dead. He went back to the Earthman, stared down for a moment. There was no doubt that he had unwittingly saved Ketrik's life.

"Guess you served your purpose here, after all," Ketrik murmured, but his thoughts at that moment were not as calloused as the words.

With a few strokes of his electro, he removed the crystyte globe of radium from the ceiling; and carrying this light, he was no longer bothered by the scavengers. For hours he proceeded along the tunnel. At last, infinitely weary and wracked with pain, he reached a blank wall.

Searching around it, he at last found a loose stone which he pulled away. A tiny metal lever was revealed. After tugging interminably at it and pounding the rust away, Ketrik managed to pull it slowly back.

The entire wall swung around on pivots. A blast of foul air struck him. Ketrik stepped into a small passage. He recognized it as one of the underground sewers of Turibek. He followed it and came to a short flight of stone stairs leading up to a hinged door. Slowly he shoved it open.

He was in Turibek! This was one of the narrow, winding streets in the warehouse district. He glanced at the sky. It was night. Deimos was gone below the horizon, but Phobos rode high on liquid sapphire.

Ketrik rested there for a few hours until Phobos descended. Then, in the utterly dark hour that precedes dawn on Mars, he crept forth and sought the shop of one Jal Thurlo in the Street of the Double Moon.

IV

He found the shop, in a twisting little street that seemed to cringe from the rest of the city. The insignia of Jal Thurlo was still upon the door, and Ketrik breathed a sigh of relief.

Finally, after his persistent knocking, the door opened a trifle and Ketrik saw the wizened little face of Jal Thurlo. The shop-keeper's eyes were dark with suspicion.

"I was told I would find one Jal Thurlo here," Ketrik said glibly. "I come with news of a secret shipment. Rare kaladonis furs from the plains of Io."

"At this ungodly hour?" Thurlo grumbled sleepily.

"It is the proper hour for such matters, thou sulky one! Permit me to enter now or I take my news elsewhere!"

Thurlo opened the door, and Ketrik slipped into a dark room that smelled of spices, perfumes, and a miscellany of objects from the far planets. He followed the little Martian through the shop and along a dim corridor, until they arrived at the living quarters. There, under brilliant light, Thurlo faced him. "Who sent you?"

Ketrik answered carefully. He knew this little man carried a needle-gun in his sleeve and had used it on occasion. "No one. I merely seek haven here. I once saved your life on Deimos—you remember it?"

Thurlo started visibly. "Ketrik! Is it really you? But no, it cannot be!"

"It's Ketrik, all right. But 'Khosan' for the time being. Remember this?" He bared one arm and revealed a long jagged scar from shoulder to elbow. He further proved his identity by recounting the adventure on Deimos many years ago, in which he'd received this scar while saving Thurlo's life. "I must remind you of the Martian blood debt," he ended. "I saved your life and it is forfeit to me until you repay."

"I have not forgotten!" He looked at the other's torn and bleeding legs. "Come, man, let me dress those wounds! Then you can tell me why you are here."

Ketrik recounted part but not all. When he had finished, impressing upon Thurlo the urgent need to get inside Dar Vaajo's laboratories, the little Martian shook his head.

"I fear it cannot be done. That part of the city is strictly forbidden. Vaajo's palace is there, and the homes of his scientists, all surrounded by the wall. Even the few servants who are permitted to pass in and out occasionally are painstakingly examined."

"I've got to get in there," Ketrik reiterated. "And I intend to!"

"Wish I could help you. It might be for the best! Dar Vaajo is becoming as hated as he is feared, yes even by his own people! Something monstrous and mad is going on in those laboratories!"

"What can you tell me about it?"

Thurlo's eyes became dark, and his voice lowered. "Only this: Frequently, in the dark of night, a faint greenish glow comes over the city. It only lasts a few seconds, then withdraws into a pillar of concentrated fire directly over the laboratories! Then it seems to extend itself, lashing outward into space."

"Greenish fire!" Ketrik exclaimed. "Do you mean electronic power, Thurlo?"

"No, not that at all. I'm no scientist, but I know this is cold light. It's different—devilish! You may laugh at me, Ketrik, but I will say it. These radiations seem alien to this world, to this universe; they seem almost—alive!"

But Ketrik did not laugh. He was remembering the mad survivor of a missing Earth spacer. He was remembering the poor gibbering devil he had seen but recently in the tunnel. He thought of these and other things, and felt the hair at the back of his neck begin to rise.

"Why," Thurlo was grumbling, "did Vaajo have to come here to conduct his devilish experiments? Why could he not have stayed in the northern capital?"

"Because here he is in close contact with the Rajecs," Ketrik said experimentally, and watched for the little Martian's reaction.

"Yes!" Thurlo nodded. "I can tell you something about that, too. Under the treaty, the Rajecs are allowed access to Turibek or, if they wish, other cities to the north. Vaajo has even built a magnificent temple here, where they can carry on their own ritualistic worship. Well—I've seen those black caravans come into the city, quite a number of them in the past weeks. But one sees little of them afterwards! Of course they may be shunted further north...."

"No!" Ketrik smacked a fist into his palm. "No, Thurlo, for some reason they are needed here! It's all a part of Vaajo's plan—I knew it!"

"I care little about the Rajecs," Thurlo shrugged. "It is well that they disappear."

Ketrik thought differently. He lay awake in the little cubicle to which Thurlo assigned him, his mind too turbulent for sleep. The pattern, though still vague, was beginning to take shape. At least he had gained entrance to Turibek! Tomorrow he would make a short tour about the city, try to formulate a plan. At last his tired muscles relaxed, and he dropped into an untroubled sleep.

It was high noon when Jal Thurlo wakened him. The little Martian seemed strangely perturbed. "My friend, there is one at the alley entrance who asks for you!"

"For me?" Ketrik was up instantly and began dressing with deft, precise fingers. Who else would know that he had arrived in Turibek? But his mind was put at ease when he reached the rear entrance. Standing before him was the somewhat bedraggled but still grinning figure of Aarnto, the caravan leader.

"Did I not say, Khosan, that the day would soon come when you could repay me? I remembered well your mention of this shop!" And when Ketrik hesitated, he went on, "Well, O fugitive of the dark tunnels—am I not permitted entrance?"

"Come in—quickly!"

Aarnto waved a hand cheerily. "There is no need for alarm. I entered through the city gates as I said I would. The others have gone to the temple, but not I. I will need a place...."

Thurlo frowned. Ketrik said, "It's all right, Thurlo. Aarnto's a friend of mine. Please allow him to stay. I owe a debt too." He turned to Aarnto. "But listen! Don't draw the Specials here. I can't afford that!"

"I am caution itself, my friend! I too have a mission here. Perhaps one night's sanctuary is all I shall ask, and your debt is paid." The black still smiled—with all but his eyes. Behind them Ketrik detected a hardness and cunning, together with a warning not to ask questions.

Ketrik had no intention of doing that, but he made a resolution to watch this one. If their paths here should ever chance to cross, Aarnto would be a tough one indeed! Ketrik left him in Thurlo's capable but somewhat reluctant hands, while he prepared himself for his tour of the city.

From the Street of the Double Moon, he emerged into the broader thoroughfare. Turibek was the metropolis of the south, boasting of theatres, cafés and shopping centers, as well as a magnificent spaceport.

Ketrik gave but a glance to the overhead mono-cars, preferring to stroll leisurely. He found the people, the streets, and the queer facaded buildings much the same as he'd know them years ago.

There was one startling difference. At the end of this main thoroughfare a forbidding wall reared up, to extend out of sight in either direction. That was the wall around the laboratories. Ketrik could not possibly see what lay beyond.

He made his way slowly in that direction. Thurlo had furnished him with apparel that stamped him as a prosperous, somewhat foppish Martian, perhaps a mercantile buyer. He stopped once, listened to news blaring from a public Tele-system, but it contained nothing of consequence to him—no mention of Dar Vaajo or local events.

A few minutes later he entered a tiny shop dealing in rare spices and tobaccos. He purchased a vile but expensive Venusian cigar. He lighted and drew upon it with evident relish.

"Ah, we do not find these often in Roktol!" he said to the proprietor, naming a city far to the north. "Turibek has its advantages after all."

"You are a stranger here?"

"Yes, I have just arrived. I am a buyer for Varik's." He saw the man was impressed. "I find Turibek a fascinating city, but tell me—the high wall to the east of here—what is it? They would not allow me to pass!"

"And no wonder, sir. Those walls surround the palace grounds and laboratories of our Emperor!"

"To be sure! I should have known that." Ketrik smiled, and when he spoke again there was the slightest hint of mockery. "Ah, but you of Turibek should be flattered that our Emperor chose your city to carry on his noble experiments."

The man hesitated, glanced around, but decided to speak. "I think you know we are not fortunate, sir. What Dar Vaajo is doing may be for the best ... but if only we were informed!"

Ketrik raised his brows in puzzlement, and the other went on, "Eh, then you do not know of it? But of course not—you have just arrived. Well, sir, it is to come again tonight—at two hours past the midnight. This morning's Tele-news warned all residents to stay in their homes at that hour—and we know what that means."

Ketrik knew, too. The green radiance which Thurlo had spoken of. Tonight! He wanted to observe that display! Then he thought of the Rajecs, the caravan of two hundred which had just that day entered the city. His mind leaped. Was it mere coincidence, that upon this very day...?

He said carelessly, "I have heard that more of those wretched Rajecs were permitted entrance this morning. It seems a stupid thing, this treaty which allows the outlanders to pollute our cities!"

"It would seem so, yes. But Dar Vaajo is cunning in his way. Perhaps the blacks are shipped north, to work the Uranium mines!"

Ketrik dared ask no more questions. He left the shop and continued his stroll toward the wall. When he came within a block of it he could see that it wasn't stone, as he had supposed. It was heavy mesh-duraplon reaching twenty feet high, and still higher were the electronic control-towers. A touch of a button would throw any section of this wall into flaming, deadly radiance. Here was a formidable barrier! Ketrik frowned, looking at it—but he didn't dare linger there too long.

He turned back, was crossing the street when he heard a warning shout and then a clarion-blast. He leaped to the curb just as a vehicle swept by. It swerved sharply to avoid hitting him. Two others followed—they were the three-wheeled, electronic-powered cars native to Mars.

From the rear seat of the second car a girl's face peered out, a bit frightened at the near accident. A golden face, lovely, with copper-hued hair tumbling in waves to her shoulders, and eyes large and blue as asterines.

This much Ketrik saw, before the cars were gone. He turned and stared. A section of the duraplon wall slid upward and the cars passed through; all, except the last one. It turned sharply and came hurtling back to where Ketrik stood. A pompous Martian climbed out, strode angrily up to him.

"You! Dolt! The Princess Praana might have been injured! What are you doing here anyway, so near the grounds? Do you not know it is forbidden?"

The Princess Praana! Yes, now Ketrik remembered. Dar Vaajo had a daughter—she had completed her early education at one of Earth's best schools. That was all of ten years ago, but she had been a pretty child even then.

"Well! Answer me! Or shall I take you to the Guards for questions?"

Ketrik came out of his reverie and looked at this man. A high-servant at the palace, probably, judging from his manner. Ketrik bowed coldly.

"I was not aware of the restricted area. I am but newly arrived in Turibek, and have found your city most charming—until now." There was the correct amount of annoyance in his voice, plus a subtle warning. "You wish to see my credentials, sir?"

The other's manner changed. For the first time he seemed to notice Ketrik's dignified dress and manner. He hesitated.

"I don't suppose that will be necessary, sir. A thousand pardons for speaking so hastily, but our nerves have been on edge, you know, ever since the rumor that some of the S'Relah would attempt to enter the city."

"My dear man! I am sure our Emperor's splendid Guard can deal capably with these S'Relah! I will bid you good day now; I have yet to visit your charming shops." Ketrik turned haughtily, began his stroll back to the main avenues. He felt the Martian's puzzled gaze upon him, but did not look back.

He did not look back until ten minutes later, when he had the eerie sensation of being followed. He spotted the man at once, undoubtedly a Special—tall, cold-eyed, a bit too leisurely of manner. Ketrik smiled grimly, and entered a shop. The man followed. Ketrik came out, and the Special was just the correct distance behind.

At the next loading platform Ketrik purchased a ticket, waited until one of the mono-cars dropped down from the single overhead track. He entered the car, walked the length of it and exited on the opposite side. He hurried across an area-way and lost himself in the crowd waiting for the opposite-bound car which just then hove into view. The simple ruse worked. He boarded this car and there was no sign of his pursuer.

Dusk was fast coming upon the city when he again made his way to Thurlo's shop. His mind still wrestled with the problem of the electronic wall, and how to get beyond it. He immediately discarded the idea of an aero-copter in the dead of night; there would surely be detector rays. Here was a problem that called for planning, and patience.

And something else vaguely bothered him. A vision intruded upon his thoughts, annoying but persistent—the vision of a girl's face, lovely and golden....

V

He entered the shop, and was startled to see a Rajec emerge from behind a counter piled high with silks and fineries. The black was tall, elderly, a bit stooped, with a nervous twitch at the side of his face.

"Ah, sir, welcome to the humble shop of Thurlo. May I assist you in a selection? Some of these rare laces from Io, perhaps—or these exquisite candelabra? Over a thousand years old, sir, yet they have found their mysterious way here from the Deimian Temple of the Ancients."

Ketrik smiled a little, picked up the candelabra and set it down. "A fake. And so are you, Aarnto. I recognize you now."

"But not at first," Aarnto grinned. "I think my disguise will do. Not as thorough as yours, of course," he added.

"Where is Jal Thurlo?"

"Back there preparing the evening meal." Aarnto's finely chiselled nose wrinkled appreciatively. "And a welcome repast it will be, after our miserable desert fare!"

Thurlo had not spared his talents, and the meal proved to be excellent. Ketrik ate appreciatively but in silence. Thurlo hardly touched the food, seemed perturbed over something. Only Aarnto was his old self—more than that! His crisp manner, which Ketrik had noticed earlier in the day, was gone; he now seemed happy and almost jovial, as he kept up a running conversation. He told of haggling with one of the customers over a set of Venusian tapestries, finally getting twice the expected price.

"And look at this," he held to the light a crystalline jar that adorned the table. "Would you look at it, Khosan? Vanadol, the nectar of the Gods! An ancient vintage, too! I found it hidden away, far back on one of the dark shelves. I am sure," he smiled slyly, "that our host can obtain more where it came from, so let us drink to this occasion." He poured the blue liquor into their cups. "Yes, Khosan, an occasion—that two such as you and I should find our way here!"

Ketrik smiled, barely touched the stinging liquor to his lips.

When they had finished the repast, Aarnto rose and excused himself, but stood a moment hesitant. "I must leave you now, and I may have no occasion to return here. I wish to thank you, Thurlo, for you have been most gracious. And you—Khosan. We have been helpful to each other?"

"Yes, Aarnto. You more than I."

"Then the debt is paid." With that, the black was gone, out into the night which swallowed him up.

Thurlo sighed. "I hope he never returns. I do not like that one! If he is caught, and it becomes known I harbored one of the S'Relah here, even for a day.... I only did it for you, Ketrik."

"You needn't worry. He's a clever one. But I wish I knew what they were up to!"

"They'll fry on Dar Vaajo's torture plates," Thurlo prophesied.

Ketrik thought of his own fate if he were caught, but quickly put it out of mind. "What do you think they're up to, Thurlo?"

The little Martian spoke slowly. "The S'Relah? They are apart from other Rajecs. Treaties mean nothing to those fanatics. They wish to strike at Dar Vaajo, and"—he hesitated—"what better way to do it than through his daughter?"

The Princess Praana! Of course that was it! A bold stroke, but just such a one as the Society of S'Relah would attempt. Ketrik realized now that some such thought had been hammering at his mind all the afternoon. He said eagerly, "Tell me about her, Thurlo. I caught a glimpse of her this afternoon."

"You did? Yes, she visits the shops occasionally, always accompanied by a bodyguard. The Palace Guard has been doubled too, since these rumors of the S'Relah. I'll wager her father would be furious if he knew she had left the grounds this afternoon! But that girl has a mind and temper of her own—so I have heard."

"Has she been here long?"

"No, she flew down from the northern capital only a few weeks ago. That was against Vaajo's orders, too. I think he'll be sending her back soon."

Ketrik remained thoughtful. He failed to see how Aarnto and the others hoped to reach her! For a Martian to get beyond those walls would be a ticklish problem; for a Rajec, it would be impossible! He heard Thurlo again.

"That's why I'm worried, Ketrik. Attention is being drawn to my shop. This afternoon an elderly matron came in—I recognized her, she's been here before, one of the Princess Praana's personal servants—"

"Go on!" Ketrik was listening now.

"Well, Aarnto was in the front of the shop. He sold her some Ionian laces, then I saw him speak to her in an undertone and hand her a folded note. He doesn't know I saw him. I don't like it, Ketrik. I—"

"A note!" Ketrik's mind was racing with the speed of atomotors. "To be delivered to the Princess, no doubt! Thurlo, tell me—does Praana ever come here?"

"She would never deign to set foot in this humble part of the city. But she has undoubtedly heard of my shop...."

"That's it, Thurlo. I think I see their plan now. If you will promise to retire early tonight, I can guarantee that no word of this will reach the Emperor's ears."

Thurlo would have promised anything. An hour later all lights were out, and Ketrik stood in the darkened front of the shop where he could see the street but remain unseen. If his surmise was correct, he could thwart the plans of the S'Relah. Ordinarily he wouldn't have bothered, but now he thought he could turn it to his own advantage.

The hours passed. He watched the slow climb of Deimos across the sky. Its light scarcely touched this cringing little street. Once he saw the dull lights of a freighter descending, and remembered that just beyond this district was the freighter spaceport. Occasionally a skulking figure passed, keeping to the shadows. Once the flash of a heat-pistol came from a nearby alley, and a moment later the sound of running feet.

Still he waited. He lit a cigarette, keeping the glow of it carefully hidden. He began to wonder if the Princess would venture into this place after all. It seemed most unlikely, at this hour! It had been a crazy idea to begin with. He was clutching at straws. That note which Aarnto slipped to the servant might have meant something else entirely.

Ketrik dropped the cigarette, ground it savagely underfoot. Then, with a sharp intake of breath he leaned forward, peering through the window. From the nearby corner a dark vehicle had glided into the street! It moved swiftly and silently. It could only be one of the three-wheeled cars.

It stopped across the street from the shop of Thurlo. For a minute no one emerged, and Ketrik knew the occupants were surveying the shop. He drew back a little. Then two figures stepped out, started across the street. One was a woman. Her steps were unhesitant, even a bit excited. Ketrik recognized the Princess Praana even from here. The other was a man, who seemed to be remonstrating with her.

"The fool! The little fool," Ketrik muttered. "But at least, she had sense enough to bring one of the Guard!"

Events happened then with blurring swiftness. The shadows came from somewhere out of darkness, seemed to glide toward the pair in the street. In a split second they were upon Praana and the man. Too late the Guard sensed the danger; he whirled, but in the same instant was sinking to the street with a Rajec dagger through his heart. The other Rajec had clapped a hand roughly over the girl's mouth, was dragging her back to the car.

In those few seconds Ketrik was tugging at the shop door. It seemed to stick. He cursed, wrenched it open and flung himself into the street. His gun was out but he saw it was too late; Praana and the two assailants were already in the car, the motor was whining to life. Ketrik reached the car in two bounds, just as it hurtled away. He flung himself blindly at it. His hands managed to grip the rear wheel-guard. He clung to it, arms wrenching painfully as he was dragged along.

The car slowed, turning into the nearby street, and Ketrik managed to get his feet up. There he crouched precariously, leaning his weight forward as the car jolted through rough streets and alleyways. Again he cursed. He'd lost his gun back there! He didn't think they'd seen him, though; Praana had fought like a wild hella.

They apparently had her under control now, probably had administered a drug. Ketrik began to take notice of their direction. They were deep in the dark warehouse district. Suddenly his heart leaped. He knew where they were going! They intended to get Praana out of the city through that secret Canal-tunnel! He doubted if there were a dozen men in this city who knew of its existence, much less its location.

Then they reached it. Ketrik recognized the place, knew he'd have to act quickly. One of the Rajecs had gotten out, was leaning over, trying to lift the girl's limp figure down from the seat. Ketrik stole forward. He put all his weight behind the blow which landed at the side of the man's neck; it was a dirty blow but this was no time for niceties. The Rajec crumpled, slid forward against the car.

"What's the matter, Vronu?" The other was Aarnto; Ketrik recognized his voice. Aarnto came around the front of the car then, and took in the scene.

Ketrik was tense. But Aarnto didn't move or speak. Not for several seconds. Then he said, slowly, "So. It is you again, Earthman." He was calling the terms correctly now. "I thought I had seen the last of you."

Ketrik glanced at Praana's unconscious figure upon the seat. His eyes flicked back to Aarnto. "My debt is paid, Aarnto! You said it yourself." With that, his limbs uncoiled and he hurled himself forward.

Aarnto met his rush, sending out a straight jab as he allowed his body to sway aside. The blow was glancing but powerful enough to send Ketrik off balance. Ketrik's lips went tight as he whirled back to the attack. He knew he had his work cut out for him here.

Aarnto seemed slim, but there was weight there and he knew how to use it. He put it behind every blow. For a few seconds Ketrik found himself parrying these blows, ducking and rolling and taking a few on the arms which numbed him. He managed to get a few past Aarnto's guard, but the Rajec took them too, and pressed his advantage. Ketrik was satisfied to back away for the moment. His legs were still a little numb from crouching on the car.

A crashing right came through Ketrik's guard, drawing blood from his mouth. He countered and missed, as the other leaped away. Again and yet again this happened, with Ketrik missing almost clumsily; they fought in near darkness and it was hard to connect with that swift moving black body!

"So you would interfere, O crudely disguised one!" Again Aarnto's fist came through, to send Ketrik reeling back. But his legs were less numb now, and he began to co-ordinate his footwork. His brain was lightning clear. Aarnto laughed contemptuously, laughed with the joy of battle and pressed forward, throwing more lefts and rights. They missed as Ketrik danced away lightly as a hella cat—then Ketrik threw a boxer's left, long and weaving, that found its mark.

"That better, O haunter of dark places?" He followed it with a right that crashed against bone, and Aarnto didn't laugh again.

Slowly Ketrik took the initiative, refusing to give way now and throwing his long left to advantage. He used the other's feral eyes as a focal point, aiming just below them. He sensed that the other was weakening. Aarnto gave ground slowly, fighting back. His blows were still heavy but now his timing was off and Ketrik didn't give him a chance to regain it. Ketrik's own arms were becoming numb, from stopping the other's blows. He shifted the attack to the stomach and Aarnto's guard dropped. A right came up that sent the Rajec staggering. Ketrik leaped in for the kill, lashed with a left that sent the black spinning half around.

The right-cross that followed immediately, was the one that did it. It caught Aarnto at the point of the jaw just below his ear. By the way he crumpled, Ketrik knew he wouldn't get up for some time.

Ketrik stood there for a moment looking down. A roaring was in his ears, a vast tiredness came upon him. He wiped blood from his face and looked at his bruised fists.

A sound came from behind him. He whirled.

It was Praana. She stood there, looking small but somehow not frightened, staring at Aarnto's prone figure. She reached into her tunic and drew out a small electro. Before Ketrik could realize her intention, she aimed it at Aarnto.

He snatched the gun away just in time. "You'd kill him in cold blood?"

"He's a Rajec. And a member of the S'Relah!"

"Oh, you realize that how, do you? Well, listen to me. He fought fairly—had a dagger there in his belt, and could have used it. So he gets a break."

She turned an angry face to him, started to speak, but he stopped her with a gesture. "Quiet! Listen!"

From somewhere near came the sound of scuffing feet. Ketrik moved swiftly to a little metal door between two buildings. This was the door to the sewer, which in turn led into the secret tunnel. Presently it opened, and Ketrik saw the yellowish glow of eyes. Rajec eyes, many of them—perhaps eight or ten. Ketrik stepped back. He gave a burst with the electro, allowed the beam to cut a frothing path very near the doorway. The black figures drew back.

"You get these two, and that's all!" He indicated Aarnto and Vronu. "Two of you step forward and get them. Quickly, now!" He gestured meaningfully with the weapon.

Two of the Rajecs crept out, watching him all the while. They seized the limp figures and dragged them back. Ketrik followed. "All the way! Clear back into the tunnel. I'm letting you off easy. Be glad you don't get Vaajo's torture plates for this night's work!"

He herded them all into the tunnel, then swung the pivoted door shut. A steady play of the electro-beam fused the mechanism so that it wouldn't work again, ever. He knew they might use their knives, loosen the stone blocks enough to gain another entrance, but he didn't care about that now.

He hurried back to the street, found Praana still waiting. Her fists were clinched and her voice sharp. "You take a lot upon yourself! Those were the S'Relah and should be turned over to the Guard!"

Not a word of thanks, no show of gratitude. Ketrik let his own voice rasp. "It isn't important. You were a little fool to leave the Palace! Why did you do it?"

"Then you know I am the Princess Praana! And you—you dare to speak to me like that!" She raised her fists, seemed about to strike him—then a thought occurred. "Rilon—he—where is he? What happened?" Then she shuddered, as though suddenly remembering.

"I suppose you mean your Guard," Ketrik said with no attempt to spare her feelings. "He's lying back in the Street of the Double Moon with a dagger through his heart, thanks to you."

"Thanks to me," she whispered, all the spirit gone out of her now. "I shall never forgive myself! He warned me, tried to stop me, even pleaded—and when I threatened to come alone...."

Ketrik said sternly, "Why should you want to come at all—to this miserable part of the city?"

"You are right, I was a fool. Occasionally I send a servant to the shop of one Jal Thurlo, to pick up a rare article that would never find its way to Mars by the ordinary routes—you understand? This afternoon my servant brought me exciting news. In his shop Jal Thurlo had a single bottle of the perfume from the Deimian Temple of the Ancients! Can you understand what that means? That rare, that glorious perfume...."

Yes, Ketrik could understand. He smiled at Aarnto's cunning. Women would give their money, their jewels, everything they held precious, for a single dram of that perfume which was so rare as to be almost non-existent.

"But," Praana went on, "it was to be smuggled away from Mars tonight! It was to go to the Princess Aladdian on Venus! The note said that if I were to see Jal Thurlo tonight, I might persuade him—"

Ketrik felt suddenly sorry for her. She was almost in tears. "It was a trick of the S'Relah," he said, "and Jal Thurlo knew nothing of it. As for the Deimian perfume—my dear girl! I happen to know that the last of it was smuggled to Earth some years ago, and sold for a fabulous price." Ketrik neglected to mention that he himself had engineered the feat.

She smiled wistfully. "You have saved my life, and I have learned a great lesson. I owe you for both." She suddenly removed a bracelet of Martian diamonds. Ketrik waved it away, and she frowned in puzzlement. "Is it not enough?"

It was not nearly enough. What he wanted was to get beyond the electronic wall. He came near to hinting at it, but checked himself. No need to press his luck too far.

He bowed elegantly. "To have been of service to you, Princess, is reward enough in itself."

She was impressed, insisted on knowing his name and where he could be reached. He gave her the information with seeming reluctance. She assured him she could make her way back to the palace alone. "You shall be rewarded, nevertheless," were the last words Ketrik heard as she drove the car away. And he smiled inwardly.

He was jubilant, retracing his route through the dark streets. Dar Vaajo would certainly send for him tomorrow! For he knew that Praana would tell her father of this.

It was just past the midnight hour, and suddenly he remembered something. This was the hour ... but even as the thought crossed his mind, the phenomenon came. It came as a greenish glow rising above the city center, spreading swiftly outward. As it spread, like a blanket of palely pulsing light, a frightening malignancy came with it.

Then it touched upon Ketrik, and he reeled. The cold light was all about him, surging through him. Tightening tendrils of it clutched at his brain. A vast singing was in his ears. He fought back, fought as his mind reeled upon a chaos of vertiginous horror! Those light-tendrils tearing at his brain, eagerly, hungrily—here was Dar Vaajo's weapon and he knew it, even as he fell to the street to lie exhausted, his mind going away....

Still he tried to fight, knowing it was hopeless. An agony was in him, tearing at his fingertips and through every muscle; wrenching at his brain, seeking to tear it apart fiber by fiber. He felt his sanity going; it was being drained away as liquid is sucked through a straw. He laughed once, wildly. He felt other light-tendrils seeking, seeking hungrily all about him. With a last vestige of mental power he remembered again a gibbering madman in a dark tunnel....

Then the light was going away. It receded, rushing back upon itself, coalescing into a mass of greenish radiance that swirled and twisted angrily and tried to escape. Almost alive! As Jal Thurlo had said! Ketrik rose and stood swaying, his head throbbing, as he watched it from afar.

Now the spherical mass of it, deeper in hue and pulsing angrily, hovered in the sky just above Vaajo's laboratories. Suddenly the sphere extended, became a pillar of pulsing light trying to leap away.

And it leaped away. Faster than light, swift as thought, hurtling through the outer reaches of space.

Ketrik didn't stay to see more. He didn't need to. Even through the cold needle-fires in his brain, he had enough faculty left to know that far out in space, in that part of the heavens, swam the planet Earth. Again this night Dar Vaajo was testing ... testing the power of his curiously-alive weapon....

Ketrik reached the shop of Jal Thurlo, found the jar of vanadol and downed enough of it to put him into merciful oblivion.

VI

It was late the following day when a car, bearing the royal insignia, drew up before the shop and one of the Guards asked for "Khosan."

Ketrik was ready. He'd been waiting for this. As they drove toward the palace grounds the two Guards looked at him enviously.

"You have won great favor with the Emperor for last night's work," one of them said. "He wants personal audience with you! It would not surprise me if he made you Captain of Praana's own guard!"

"It is true you were not supposed to be on the streets at that hour," said the other. "But Dar Vaajo will overlook that, considering the circumstances."

Ketrik remembered that Praana was not supposed to be on the streets either, but he didn't voice the thought. They reached the electronic wall. One of the men gave the signal, and a section of it moved upward. Their car passed through.

At last he was inside the forbidden grounds! Ketrik remained outwardly humble, but he kept his eyes open. They went along a sweeping drive bordered by stately majagua trees. They passed a few buildings, fronted by splendid lawns. Then the palace itself loomed ahead, a magnificent two-storied structure of dark culchite marble.

But Ketrik had no eyes for it. To the left was a building equally imposing, and covering more area, which could only be the royal laboratories! It was undoubtedly from that building that the phenomenon had come the night before. He noticed the roof in particular, glass-covered, curving into a shallow dome. If Dar Vaajo favored him, he could get a position in there....

Then they were past the building and approaching the palace. The audio-tube near the driver's head crackled to life, and a voice came through. Ketrik couldn't hear the words. A startled look appeared on the Guard's face. "Are you sure?" he said. "My orders were—"

"These are new orders! Obey them!" Ketrik heard those words all right. The audio went dead. The driver wheeled the car around abruptly, headed away from the palace.

"Something wrong?" Ketrik asked.

"Plans have been changed. Dar Vaajo doesn't want to see you quite yet." The man's voice was grim.

Ketrik felt a sudden foreboding. "Where are you taking me, then?"

No answer. Ketrik glanced at the Guard sitting next to him. This man had gone grim too, as his hand rested lightly on the electro beneath his tunic. Ketrik couldn't guess what had gone wrong or why, but he knew he wasn't going to see Dar Vaajo under favorable circumstances. He went tight inside.

They stopped before a low stone building. The driver came around, opened the car door. "Out!" he ordered curtly.

Ketrik came out. He launched himself bodily, his fist smashing to the other's face and making a bloody smear of it. The man staggered back. The momentum carried Ketrik out of the car and to his knees. He heard the rush of the other Guard, whirled to meet it. Too late. He only saw the dark blur of the man's arm coming down in a swift arc, then heavy metal crashed behind his ear, leaving him stunned.

His muscles wouldn't pull him up. The blows came again ... more than once, heavy and accurate. He ploughed forward onto cold pavement as his mind blanked out.

He came again to consciousness, groaned as heavy pain hammered through his skull. Gradually his eyes focused upon the details of the room. There weren't many details. It was a small room, quite bare. The floor was stone but the walls seemed to be of thick crystyte. Dim lights filtered through. There was no entrance of any kind that he could see.

"So you are awake at last, Earthman. And none the worse for wear." The voice came from within the room. Ketrik raised his head, stared at the opposite wall, a section of which had taken on the silvery radiance of a tele-vise.

Imaged there were the features of Dar Vaajo. Ketrik recognized him immediately.

It was an elderly face, but smooth—with the color and toughness and texture of old leather. The lips were tight and purposeful, the cheek-bones bulged beneath crisp, graying hair. And the eyes ... they held Ketrik. They weren't old eyes. They were hard and bright as jewels. An indomitable light came up from the dark depths of them.

Dar Vaajo spoke again from the screen.

"As you see, I prefer to hold audience with you in this manner. You are a dangerous man. Yes, very dangerous, to have come so far. Through my Space Patrol. Past my Specials. Into the city and past the inner wall itself." The lips quirked a little. "Yes, I have determined everything about you. Your name is not Khosan, but George Ketrik—I have heard something of your exploits in the past. You are the spy sent here by the Earth Councillor, Mark Travers." Again he paused. "You are not surprised that I know all this?"

If he was surprised, Ketrik didn't show it in the slight shrug he gave. He knew the voice would go on.

"I have learned this," Vaajo said, "within the past few hours. You see—we, too, have a development of the Scanner Beam. This beam was trained upon you from the very moment you drove into the palace grounds. We learned your true identity and purpose."

Ketrik went dry inside. It would have to be that, the one thing he couldn't have foreseen! He spoke to the screen. "Very well, so I have lost. I suppose I can expect no reward for saving the Princess."

Something showed in the dark depths of Vaajo's eyes. Amusement? But he spoke thoughtfully. "Very well, you shall have your reward. I think I will send you back to Mark Travers—in a most unique way!"

Quite suddenly then, Ketrik knew. He knew the reason for the beam he had seen launched into space, and almost he grasped the principle of it. He felt his insides twisting up into cold, hard knots. But he managed to say, "You mean—that just a part of me will go."

Vaajo chuckled. "So. You saw last night's display, felt a taste of it perhaps, and you have guessed. Yes, your surmise is correct! We utilize the Rajec caravans. Two hundred yesterday, and fine specimens they were! But they are now mere walking hulks, devoid of all but the most meager mental impulses. Their bodies will be sent north to work the Uranium pits. Their minds have already been absorbed into my—shall we say, weapon, increasing its potential considerably."

Ketrik's brain seemed to twist inside his skull, until he could not tell whether he felt horror or fury or both. He only knew he must keep control, learn more of this grisly thing that Vaajo was conducting with human minds.... He found his own voice, hard and dry, saying, "Yes, I saw it last night, felt it ... but still I cannot understand...." He passed a hand across his forehead in seeming bewilderment. He heard Vaajo saying, "It cannot matter now, for my beam reached Earth last night ... yes, it would please me to tell you something of it! You must have heard of the ancient city of M'Tonak, lying far beneath Mars' Polar Cap. And the sentient thought-force that came from outer space, or another dimension—no one ever knew—to land at M'Tonak where it remained for untold centuries. Through all that time the Entity remained barely alive, unknown to man, sustaining itself by sending out invisible radiations that fed on Martian minds! And you must have heard of the Earthman, Jim Landor, who found his way there and destroyed the Entity, leaving it crushed beneath tons of ice. All this was before your time or mine. Over a hundred years ago...."[3]

Ketrik nodded. He had heard the story many times.

Dar Vaajo went on. "The story of the thought-entity beneath our ice cap had always intrigued me," he said. "So several years ago I sent some workmen to uncover that ancient city. Yes, you have guessed. The Entity hadn't died! It remained there insentient but alive, frozen into suspended animation beneath miles of ice! It was then that I remembered the stories of its power, its insatiable appetite for the mental forces of man ... and thereupon I evolved my scheme. It has been dangerous, Ketrik, but I worked slowly and carefully.

"The first step was to waken it, which was easy. The second step was to keep it under control—not so easy. But I managed this by means of Uranium rays which seems to be the only thing capable of combating the Entity's own peculiar atomic structure. That was the reason for my Uranium embargo; I've had to increase the potential of these controlling rays as the Entity grew in size and power."

"You mean you ... fed it? Allowed it to grow?" Ketrik was aghast, listening to this cold-blooded recital.

"Of course! How else was I to reach Earth with it, across miles of space? That was my ultimate goal."

"But how? It must have taken a tremendous ... surely the Rajecs were not enough?"

Vaajo smiled blandly from the screen. "I told you I worked slowly. I began by communicating with it, telepathically. Yes! It's a highly intelligent entity, and it wishes to remain alive. It seems it came originally from a world in another dimension bordering on ours! It was the creation of a scientist on that world. The Entity became dangerous, threatened to get out of control, and could not be destroyed. The scientists rigged up a contra-dimensional device which hurled it out of that dimension. It landed quite by chance in ours—on Mars, near M'Tonak.

"So we made a sort of pact, the Entity and I. I wished it to grow in size and potential, but not at the sacrifice of my own people. I told it something of my plans. It, in turn, told me how to build a contra-dimensional machine by which to project it back into its own world! I managed this at last, adding a reverse control by which I could always bring it back.

"Fully a dozen times now it has crossed the dimensions. Whenever I brought it back, it had ... fed. You understand? It was satiating itself upon the populace of that other world! Until finally, it revealed to me that ... there was no more. The other-dimensional world was barren of sustenance!

"By this time, however, I was almost ready. It had grown tremendously in size and power. I always added more rays to keep it under control. Then I began testing for Earth, allowing it to reach out. Have you realized what a terrible weapon concentrated and projected thought can be? Several times it touched Earth spacers, absorbed the minds aboard them, and"— Dar Vaajo shrugged—"I had to send my Patrollers out afterwards to destroy the spacers. But never were we quite able to reach Earth! It would take more potential, just a little more, and where was I to find it? Then I thought of the Rajecs. I made treaty with them, built the temple here to attract them ... I guess you know the rest."

Ketrik knew the rest, and more. He knew that Earth would have to capitulate to Vaajo's demands, or face destruction by a mind-destroying, mind-feeding Entity now capable of reaching across space. Venus would undoubtedly be next, leaving Dar Vaajo in control of the inner planets including the colonies recently established on Jupiter's moons.

"So, Ketrik, I shall send you back to Mark Travers," Dar Vaajo was saying. "Four days from now the orbits of our two planets reach their nearest juxtaposition. Then is when the Entity shall reach out again for Earth, to give another sample of my power." Vaajo smiled maddeningly just before he caused the screen to blank out. "And isn't it ironic that you, or rather the mental part of you, shall be an infinitesimal part of it!"

VII

It seemed hours later when Ketrik awoke. He had tried in vain to find a way out of the smooth, crystyte-walled room. He had sought to loosen one of the heavy stones in the floor until, with bleeding and broken-nailed fingers, he had fallen into a sleep of sheer exhaustion.

Now, in the exact center of the room, he noticed a platter of food. He frowned, until it dawned on him that it must have been lowered from the ceiling! He glanced up, but if the entrance was there, it was tightly closed now.

He ate the palatable food, but noticed the platter was of light plastex, could not possibly be used as a weapon or anything else. He made another search through his clothes, knowing it was useless. But suddenly he remembered the tiny scanner disc which Mark had given him. He had strapped it tightly to the underside of his arm ... and it was still there!

He could think of no use for it now, however. He was still pondering this, when his attuned ears caught a faint sound of footsteps overhead. A moment later a section of the ceiling slid back. Framed in the square of light Ketrik saw a face ... golden, a bit frightened.

Praana! Ketrik's heart leaped.

"Speak softly," she whispered. "You are in a room directly beneath the main palace. Father has gone for the moment, and I took this chance...."

"Why are you here?"

She spoke quickly. "A few hours ago I tuned my tele-vise into this one. I heard everything he told you! It's horrible, what he is doing—unbelievable! I hadn't known before! I knew he was conducting some sort of experiment ... but this...." The shock of it, even disbelief, was still mirrored on her face.

"Praana, listen to me! Doesn't your father have an Ethero-Magnum here, capable of reaching Earth?"

"Yes, in his own private quarters." She was puzzled.

"You must get to it! Tune it into the Earth beam, then give me a channel from this tele-vise here, into that beam. If I can reach Mark Travers, I'll have him send the Earth Fleet!"

He saw her hesitate. She knew that Mars' patrollers could not stand against Earth's mighty armada. She was visioning the holocaust, the destruction of Martian cities and her own people. Ketrik went on quickly.

"Praana, you've been to Earth! You spent most of your girlhood there, and you must remember it still, have a fondness for it! The green forests and wide lakes, the mountains, the unreal clouds in a blue sky—and the people who treated you kindly! All this will go, unless you act. Surely—"

"Mars is my world," she was murmuring. "My own people ... to consign them to another horrible war! Mars would never recover."

"It will not come to that! If Earth takes the initiative, sends its Fleet in a surprise attack—the display of power will be enough. Dar Vaajo will be helpless in the face of it." Ketrik was not at all sure this would be the case, but here was his only chance. "Quickly ... we haven't much time!"

Praana was wavering. "You saved my life," she whispered. "Yes, I will try!" She tossed an electro-gun down to him, her own gun. Then she was gone, as the ceiling door went shut.

Ketrik waited, facing the wall which he knew was the tele-vise. Minutes passed, seemed to lengthen interminably. If he couldn't get through to Mark ... if Praana failed to gain access to the Ethero-Magnum, that was his last hope.... He wondered if she knew how to operate it!

Suddenly a pale glow came across the wall, wavered for a moment and then deepened. He was looking into a luxurious room which must be somewhere in the palace above him. At the far end he saw the magnificent Ethero-Magnum, with Praana standing before it manipulating the controls. He heard the ascending whine as selenic cells poured power into the beam, then minutes passed as it gained full strength. At last a voice came through faint and clear! Mark Travers' voice saying cautiously, "Go ahead, go ahead! You're on Earth beam."

"Ketrik speaking! Mark, listen carefully now and act fast! Mass the Earth Fleet, get it to Mars. Blast the city of Turibek clear off the planet if you have to! Things—"

"The Fleet," Mark cut in, "is already on its way, in full battle formation! Something happened here about thirty hours ago that I suspect is Vaajo's work! Touched an area just south of Kansas City. It's horrible! Everyone within that area—"

"Spare me the details, I know them anyway. Dar Vaajo plans to give you another taste in three days, on what I think will be a vastly wider scale! After that, he'll probably give his ultimatum."

"What is it he's got there?" Mark's voice was harried. "And where are you—"

"No time to tell you now! You wouldn't believe me anyway, and there's no defense against it except to get that Fleet here and fast! I only hope—"

The beam went suddenly dead. For a second the screen blurred, then Ketrik was looking into the room of the Ethero-Magnum again. But it was a different scene now.

Different, because Dar Vaajo strode swiftly into view! He approached Praana who straightened up suddenly from the Magnum's panel. Vaajo was trembling with rage, but Praana faced him defiantly. For a moment no one spoke. Then Vaajo turned, facing the screen so Ketrik could see him. Anger was still on his face, but something of triumph too.

"I really should thank you, Ketrik—and my daughter! I couldn't, have planned it better myself. So the entire Earth Fleet is coming, and I am warned! I shall wait until they are almost here before I use my weapon; yes, it should cover the entire expanse of the Fleet at one stroke! And after that"—he shrugged, permitted his cruel lips to fashion the faintest of smiles—"after that, what shall I have to fear from a Fleet manned by mindless idiots? Yes, it will be a master stroke! Again I thank you."

He flicked off the control. The screen before Ketrik's eyes went dead, almost as dead as the hope within him.

The Fleet might have gotten through and taken Vaajo unawares, if it hadn't been for him! Now Vaajo was warned, and Ketrik knew it was no idle boast he had made. The awful power of the Entity was quite capable of dealing with the Earth Fleet, especially as the Commanders had no idea of the type of thing they were facing. That it would strike suddenly and completely, Ketrik had no doubt.

His soul was bitter within him. He had but one chance left, a wild and improbable chance, but he mustn't miss! It was hours later when he again heard footsteps overhead. He threw himself to the floor, pretended to be asleep. The electro was in his hand, carefully concealed beneath him.

As he thought, it was a Guard bringing him food. From lowered lids he saw the ceiling trap slide back—slowly at first, then wider. The Guard leaned over, concentrated on lowering the platter of food on a long cord. When it had almost touched the floor, Ketrik brought out his hand and fired. It was simple as that. The man's body toppled through the opening, made a dull thud on the floor below.

So far so good, Ketrik thought grimly. He bunched the dead man's limbs under him, stood upon the sagging shoulders and leaped for the opening. A moment later he was swinging his body up and through.

He was in a dim, carpeted corridor, probably part of the servants' quarters. He hurried softly past a row of doors to the end of the hall, then up a short flight of stairs. A heavy door faced him. He pushed it open cautiously, then stepped out into a small flower garden. It was night, but Phobos was making a brilliant path across the sky. Unfortunate. But he'd have to make the best of it now.

He hugged the shadows until he got his bearings. This was the rear of the palace, he realized; at least that was lucky, for it brought him closer to that glass-domed building which he was sure was Vaajo's laboratory. It should be somewhere to the left of here.

Swiftly he crossed the garden. He passed through a tall hedge which concealed him from the palace. He followed the shadow of it all the way to the left, until he came in sight of the laboratory building. It was lying only fifty yards away—but fifty yards drenched in Phobos' glow!

He hesitated. But there was no other way. He started across the space leisurely, remembering he was still "Martian." The building was dark, there seemed to be no Guards about.

He was wrong in the latter surmise, he learned when he had almost reached the building. A voice challenged him. Almost in the same instant he saw the man, deep in the shadow of an arched doorway. Ketrik veered toward him, grunted something in reply and raised a hand in casual greeting. The Guard hesitated. Ketrik came two steps nearer. The Guard dropped a hand to his gun, and Ketrik hurled himself forward—low and hard.

The impact carried the Guard backward. Their combined weight crashed into a door, nearly taking it from the hinges. Ketrik rose quickly but the Guard didn't rise at all, and Ketrik knew his luck was still with him.

He changed his mind a second later. He heard shouts and pounding feet. Guards were all about the place, probably stationed at each of the doors! For a split second Ketrik hesitated. The only way now, was in.

He hurled his weight forward and the already weakened door crashed open.

He hurried recklessly forward through darkness. He touched a smooth marble wall, allowed his fingertips to brush lightly along it as he ran. His racing feet sent up echoes in the hollow place.

The Guards were crowding through the doorway behind him now. Suddenly lights leaped up! Just as suddenly, Ketrik swerved aside. An electro-beam hummed, came so close to him he could feel the swirling heat. He hurled himself into a dim cross-corridor, as more electros lanced out. But Ketrik was expert at this game. He raced for a stairway he could see just ahead. He was halfway up when the others came into view below him. He whirled, gave a sweeping burst with his own gun that sent them tumbling back out of range. He gained the second floor corridor.

Suddenly the lights came on there too! Someone at the master-switch was throwing on light all over the place! Ketrik preferred darkness. He couldn't keep this up interminably. Feet pounded on the stairs now. He opened the nearest door, slipped into a dark room. There he stood breathing heavily as the pursuers pounded by. He waited until their footsteps died away, then opened the door a crack.

It was almost his undoing. A beam creased his hair. He drew back, then suddenly flung the door wide and fired at the man they had left to guard the stairs. His beam sliced across the Guard's wrist, sent his gun spinning. But the man's scream of pain sent up shrill echoes that would bring the others back. Ketrik bowled the man aside as he leaped for the stairs leading up. At least he'd gained a few minutes!

He wasn't fleeing blindly now. He had an objective. He was sure the place he sought lay above—somewhere near that great, curved glass roof. He reached the third floor and continued upward. Then he groaned. The stairs ended at the next floor. A heavy metal door barred his way. He wasted precious seconds fumbling at the complicated mechanism—was about to use his electro to burn it away, when the great handle slid down under his pressure and the ponderous door swung aside. He leaped forward into more darkness.

There he paused, electro raised. This would be cutting off his own retreat, but he had to do it now! The beam lashed out, played across the door's inner mechanism. Gradually the tough metal fused under the heat. Ketrik made a thorough job of it, was satisfied at last that it would take them some time to blast through!

But he couldn't hear them out there. They should have reached the door by this time. He frowned, then drew out the short-wave scanner disc. He pressed the stud and tiny coils hummed to life. He moved the sliding sheathes around the rim and at last a thought-impression came through—a jumble of them. Ketrik knew his pursuers were standing on the stairs, hesitant and a bit frightened, staring at the metal door. Then a stronger impression came out of the thought-jumble as one of the Guards spoke. "Shall we go ahead? We can burn through the door."

"Enter that place?" came an answer, and Ketrik felt the mental shudder that came with the words. "I'd sooner go unarmed into a den of hellas!"

Other thoughts agreed. Ketrik grinned there in the dark. He knew now, that somewhere beyond him must be the lair of Dar Vaajo's Entity, and these men were deathly afraid of it. Finally another thought stabbed through.

"Very well. There's no retreat for him now anyway. We'll wait here, but one of you hurry to the palace and bring Dar Vaajo!"

Ketrik acted quickly then. He found the lights, saw that he was in a small metal-walled room. On the opposite side was another door, and near it was a tall case containing half a dozen protective suits.

He hurriedly donned one. It wasn't hard to guess what they were for. The suit itself was of light mesh-beryllium, topped by a heavy crystyte helmet. Again he brought his weapon into play, destroyed the other five suits. Let Vaajo come! He would hardly dare enter this den without protective gear!

But even within the suit Ketrik didn't feel quite safe. He still remembered the power of the thing he had felt the previous night. His stomach turned over in a frightened yawn as he stepped through the opposite door.

VIII

He was on a wide balcony. Near at hand was a tele-vise, a control-studded panel, and other complicated machinery. Overhead, seeming so near he could almost touch it, the great laboratory dome stretched out and away in its vast curve. While below ... was emptiness. Now for the first time he realized the gigantic proportions of this building. A hundred feet below he saw bare floor. Probably twice that distance away, straight across from him, he could make out the opposite wall. There was nothing more, nothing in all that maw of space.

Peering at the walls, he saw strange instruments protruding. Short and tubular, literally thousands of them reached from the floor to the height of this balcony, stretching away across the walls as far as he could see. Ketrik thought he knew what they were—but he had to be sure.

He looked at the controls all about him. One huge panel contained thousands of studs. He depressed one. From the far away opposite wall a ray of white light needled out and slightly downward. He swept his hand across more studs, and other beams lanced out from the four walls—dozens, then hundreds. Ketrik was satisfied. Here, he knew were the controlling rays which Vaajo had spoken of. He shut the rays off, and looked further about him.

There was only the tele-vise, and two other instruments. One was merely a wheel, six feet in diameter. The other was a machine complicated beyond anything Ketrik had ever imagined. Giant tubes, coils, and alien looking grids nestled in the bulk of it. Cables thick as his arm led to the nearest wall, thence upward to the lower rim of the glassite dome, and completely around it. From there, other cables dangled downward for a few feet into empty space.

Ketrik approached the control panel. It seemed simpler than he had supposed, but he studied it a while before reaching out a tentative hand to the first switch. The coils shrieked maddeningly, then the sound ascended the scale and passed beyond the audible. The giant tubes pulsed to life, throwing out a silver radiance. Then Ketrik reached out to what seemed to be a master-lever. He pulled it slowly toward him.

There came a sound, a sighing, which rose to tremendous crescendo as though every wind from the depths of space were sweeping in upon him! An awful vertigo as the dome, the floor, and all space between seemed to tilt crazily—into nothingness! He clung to the lever, sought to push it back. His mind reeled. Everything before him was merging into a grotesquerie of impossible angles and planes—and through it all came a twisting vortex of darkness, utter emptiness, that sought to sweep him out and away!

Then the lever gave before his surging muscles. It fell back into place. Everything came back to normal—except Ketrik. He allowed the dizziness to pass, and then grinning, he tried the stunt again! Two, three times more he tried it, with the same result, until he was quite sure of his mastery over that control.

For here was the machine he had hoped to find! Here was the means and the only means, of ridding the System once and for all of that Entity which Dar Vaajo in his madness had built up into such a weapon; a terribly alive weapon which, if allowed to go unchecked, with or without Dar Vaajo, could well become a menace to all the worlds! Ketrik realized that his task had reached the crucial point. A single mistake now, a mere miscalculation, and all would be over. So far he had only seen a manifestation of the Entity, not the thing itself. But he knew it must be here, somewhere very close—and waiting....

He stepped over to the towering perpendicular wheel.

It moved easily beneath his hand. He was tense now, watching the great expanse of floor a hundred feet below. His surmise was correct. A tiny crack appeared there, extending the length of the floor. And upward from it came light—greenish, terrible light which he'd felt before, which he knew was the Entity itself, eager to lash outward! Almost, Ketrik hesitated. But he forced his hand to move the wheel.

The crack widened as the floor moved away on either side. Gradually he could see the Entity, the very bulk of it—maddening, impossible—but there it was! Fully a hundred feet across, greenish and blinding! It was roughly globular, seemed to be a giant brain slowly pulsing and evilly alive, yet somehow it was more than that. It was quasi-amorphous, writhing and changing shape and trying to heave itself upward! Tentacles lashed out—tentacles that seemed to be solidified light, seeking ... seeking for sustenance!

It began to move upward. Up between the walls on a sliding platform, to a point just above the floor, where it stopped. Some of its light touched Ketrik, beat against his helmet and surged about him, tearing with cold fingers at his beryllium suit. In his absorbing interest he had almost forgotten the controlling rays! He hurled himself at the panel. With reckless sweeps of his hands he flicked on the studs.

It began to move upward ... to beat against Ketrik, surging ... tearing....

He had been just in time. The white rays, lancing out from the walls, now formed a gorgeous criss-crossing pattern that held the Entity in leash. It writhed and cowered. Slowly its own tentacles of light drew back. It lay in seeming quiescence. But even then Ketrik received its thought-emanations, as they crashed with frightening impact upon his brain. Yes, the thing was alive and evil. Too long had Dar Vaajo held it in subservience. It wished to escape these barriers, launch out for itself. There was sustenance aplenty on Mars, and it would grow titanically. Then would come Earth—and there were many other planets.

Perhaps the Entity sensed Ketrik's rising horror. Perhaps it guessed what he meant to do! For now, despite the concentration of rays, it tried to lash out in new fury. Ketrik laughed then, a bit wildly; laughed in mockery and joy, seeing the thing in thrall, watching its futile efforts against the barriers....

Then the laughter died in his throat. Something was happening. The rays, the controlling rays across the walls—one by one they were blanking out! One by one, then suddenly whole rows at a time!

Ketrik whirled to the control-panel. Another figure was there—Dar Vaajo! Somewhere he had obtained another protective suit, had entered silently. Now he was blanking out the control-rays, enough of them to allow the power of the Entity through!

Even as Ketrik hurled himself forward, he saw madness on Vaajo's face. More of the rays blanked off as Vaajo swept his hand down. Then Ketrik was upon him. The two metal-suited figures clashed, went spinning backward and then to the floor of the balcony in a wild tangle.

Dar Vaajo was old but he was still tough and wiry. He had the strength of a madman now. He kept Ketrik at bay as the latter sought to grip his throat. He laughed wildly as Ketrik pounded futilely at the tough crystyte helmet. Then Ketrik knew why he laughed. The damage had been done, the power of the Entity was lashing through the barriers now! A tendril of light curled about Ketrik's head. Even through the helmet he felt the insatiable greed of it, as his brain exploded in fire.

Dar Vaajo was old but he was still tough and wiry.

He forgot Dar Vaajo, managed to drag himself upward. He staggered toward the huge Vortex machine. Vaajo hurled against his legs and brought him crashing down. His brain was now a writhing agony of fire. He saw Vaajo's grinning face near his own, and knew that somehow Vaajo wasn't affected by the Entity; perhaps years of working so close to it had made him partially immune. Slowly Ketrik managed to bring his knees up under the other's body, then his feet. With his last remaining strength he lashed out.

He saw the Martian's slight body hurl backward. It crashed into the balcony's low railing which caught him just at the knees. For a moment Vaajo tottered, arms flailing wildly; then his mouth opened in what must have been a shriek as he went over the edge, over and downward, to crash a hundred feet below into the great greenish bulk of the Entity.

But Ketrik didn't see that. He was dragging himself the few remaining yards to the Vortex machine, then slowly up to the controls. Heedless now of the frantic light-tendrils that tried to stop him, he managed to turn on the control. He sank to the floor as he pulled back on the master lever.

It was through blurring eyes this time that he saw the crazy tilting of the laboratory dome and everything beneath, saw the dark Vortex twisting through from an alien space. As though in a dream he saw a rush of light, glimpsed a greenish mass hurtling outward to disappear in a convergence of crazy space-angles....

After that he remembered finding his electro which had skidded away on the floor. He used it to blast the Vortex machine into tangled ruin. He remembered staggering to the tele-vise and turning it on, and seeing Praana's face from a screen somewhere in the palace.

"Praana ... the laboratory ... your father is...." But that was all. He was sliding forward against the screen, sliding down to the floor into merciful oblivion.

He saw her face again and it was no longer startled, it was smiling down at him. He tried to sit up. A spasm of pain hit him. He heard her say, "Rest. You will be all right soon."

He was lying on a couch somewhere in the palace. Servants were hovering around anxiously. Praana sent them away. Presently she said, "I've contacted the Earth Fleet's flagship. They will be here sometime tomorrow. They come in peace."

He managed to nod. "You know about the other? Your father—he was...." He stopped the words in time, his face twisted as he thought of it.

"Don't be afraid to say it." Praana still managed to smile. "Yes, I know it now, we all know! He was mad. Mars as well as Earth owes you a debt of gratitude it can never repay." She hesitated. "I want to forget. I must get away, somewhere far away. I should like to return to Earth, for just a little while."

Ketrik grinned. He lay back. He had wanted to hear her say that.