But Earth, Bill, has not completely yielded. We are going to strike for liberty. Many years of our lives--Tony's and mine--have gone into the plan. And the toil and the sacrifices of millions of our fellow Earth men. We have at least a chance to recover our lost freedom.

But we need you, Bill--desperately.

For your own world's sake, come back. Ask for a vacation trip to Mars.

The Astrarch will not deny you that. On April 8th, a ship will be waiting for you in the desert outside Toran--where we walked the day you left.

Whatever your decision, Bill, we trust you to destroy this letter and keep its contents secret. But we believe that you will come back. For Earth's sake, and for your old friends, TONY AND ELOrA.

Brek Veronar sat for a long time at his desk, staring at the charred, wrinkled sheet. His eyes blurred a little, and he saw the tanned vital face of the Martian girl, her brown eyes imploring. At last he sighed and reached slowly for the lighter cone. He held the letter until the flame had consumed it.

Next day four s.p.a.ce officers came to the laboratory. They were insolent in the gaudy gold and crimson of the Astrarch, and the voice of the captain was suave with a triumphant hate: "Earthman, you are under technical arrest, by the Astrarch's order.

You will accompany us at once to his quarters aboard the Warrior Queen."

Brek Veronar knew that he was deeply disliked, but very seldom had the feeling been so openly shown. Alarmed, he locked his office and went with the four.

Flagship of the Astrarch's s.p.a.ce fleets, the Warrior Queen lay on her cradle, at the side of the great field beyond the low gray forts. A thousand feet and a quarter of a million tons of fighting metal, with sixty-four twenty-inch rifles mounted in eight bulging spherical turrets, she was the most powerful engine of destruction the system had ever seen.

Brek Veronar's concern was almost forgotten in a silent pride, as a swift electric car carried them across the field. It was his autosight--otherwise the Veronar achronic field detector geodesic achron-integration selfcalculating range finder--that directed the fire of those mighty guns. It was the very fighting brain of the ship--of all the Astrarch's fleet.

No wonder these men were jealous.

"Come, Renegade!" The bleak-faced captain's tone was ominous. "The Astrarch is waiting."

Bright-uniformed guards let them into the Astrarch's compact but luxurious suite, just aft the console room and forward of the autosight installation, deep in the ship's armored bowels. The Astrarch turned from a chart projector, and crisply ordered the two officers to wait outside.

"Well, Veronar?"

A short, heavy, compact man, the dictator of the Astrarchy was vibrant with a ruthless energy. His hair was waved and perfumed, his face a rouged and powdered mask, his silk-swathed figure loaded with jewels.

But nothing could hide the power of his hawklike nose and his burning black eyes.

The Astrarch had never yielded to the constant pressure of jealousy against Brek Veronar. The feeling between them had grown almost to friendship. But now the Earthman sensed, from the cold inquiry of those first words, and the probing flash of the ruler's eyes, that his position was gravely dangerous.

Apprehension strained his voice. "I'm under arrest?"

The Astrarch smiled, gripped his hand. "My men are overzealous, Veronar."

The voice was warm, yet Brek Veronar could not escape the sense of something sharply critical, deadly. "I merely wish to talk with you, and the impending movements of the fleet allowed little time."

Behind that smiling mask, the Astrarch studied him. "Veronar, you have served me loyally. I am leaving Astrophon for a cruise with the fleet, and I feel that you, also, have earned a holiday. Do you want a vacation from your duties here--let us say, to Mars?"

Beneath those thrusting eyes, Brek Veronar flinched. "Thank you, Gorro," he gulped--he was among the few privileged to call the Astrarch by name.

"Later, perhaps. But the torpedo guide isn't finished. And I've several ideas for improving the autosight. I'd much prefer to stay in the laboratory."

For an instant, the short man's smile seemed genuine. "The Astrarchy is indebted to you for the autosight. The increased accuracy of fire has in effect quadrupled our fleets." His eyes were sharp again, doubtful. "Are further improvements possible?"

Brek Veronar caught his breath. His knees felt a little weak. He knew that he was talking for his life. He swallowed, and his words came at first unsteadily.

"Geodesic a.n.a.lysis and integration is a completely new science," he said desperately. "It would be foolish to limit the possibilities.

With a sufficiently delicate pick-up, the achronic detector fields ought to be able to trace the world lines of any object almost indefinitely. Into the future--" He paused for emphasis. "Or into the past!"

An eager interest flashed in the Astrarch's eyes. Brek felt confidence returning. His breathless voice grew smoother.

"Remember, the principle is totally new. The achronic field can be made a thousand times more sensitive than any telescope--I believe, a million times! And the achronic beam eliminates the time lag of all electromagnetic methods of observation. Timeless, paradoxically it facilitates the exploration of time."

"Exploration?" questioned the dictator. "Aren't you speaking rather wildly, Veronar?"

"Any range finder, in a sense, explores time," Brek a.s.sured him urgently.

"It a.n.a.lyzes the past to predict the future--so that a sh.e.l.l fired from a moving ship and deflected by the gravitational fields of s.p.a.ce may move thousands of miles to meet another moving ship, minutes in the future.

"Instruments d$pending on visual observation and electromagnetic transmission of data were not very successful. One hit in a thousand used to be good gunnery. But the autosight has solved the problem--now you reprimand gunners for failing to score two hits in a hundred."

Brek caught his breath. "Even the newest autosight is just a rough beginning. Good enough, for a range finder. But the detector fields can be made infinitely more sensitive, the geodesic integration infinitely more certain.

"It ought to be possible to unravel the past for years, instead of minutes.

It ought to be possible to foretell the position of a ship for weeks ahead-to antic.i.p.ate every maneuver, and even watch the captain eating his breakfast!"

The Earthman was breathless again, his eyes almost feverish. "From geodesic a.n.a.lysis," he whispered, "there is one more daring step--control. You are aware of the modern view that there is no absolute fact, but only probability. I can prove it! And probability can be manipulated, through pressure of the achronic field.

"It is possible, even, I tell you--" Brek's rushing voice faltered. He saw that doubt had drowned the flash of interest in the Astrarch's eyes. The dictator made an impatient gesture for silence. In a flat, abrupt voice he stated: "Veronar, you are an Earthman."

"Once I was an Earthman."

The black, flashing eyes probed into him. "Veronar," the Astrarch said, "trouble is coming with Earth. My agents have uncovered a dangerous plot.

The leader of it is an engineer named Grimm, who has a Martian wife.

The fleet is moving to crush the rebellion." He paused. "Now, do you want the vacation?"

Before those ruthless eyes, Brek Veronar stood silent. Life, he was now certain, depended on his answer. He drew a long, unsteady breath.

"No," he said.

Still the Astrarch's searching tension did not relax. "My officers," he said, "have protested against serving with you, against Earth. They are suspicious."

Brek Veronar swallowed. "Grimm and his wife," he whispered hoa.r.s.ely, "once were friends of mine. I had hoped that it would not be necessary to betray them. But I have received a message from them."

He gulped again, caught his breath. "To prove to your men that I am no longer an Earthman--a ship that they have sent for me v.ill be waiting, on April 8th, Earth calendar, in the desert south of the Martian city of Toran."

The white, lax mask of the Astrarch smiled. "I'm glad you told me, Veronar," he said. "You have been very useful--and I like you. Now I can tell you that my agents read the letter in the cigar. The rebel ship was overtaken and destroyed by the s.p.a.ce patrol, just a few hours ago."

Brek Veronar swayed to a giddy weakness.

"Entertain no further apprehensions." The Astrarch touched his arm.

"You will accompany the fleet, in charge of the autosight. We take off in five hours."

The long black hull of the Warrior Queen lifted on flaring reaction tubes, leading the squadron. Other squadrons moved from the bases on Pallas, Vesta, Thule, and Eros. The Second Fleet came plunging Sunward from its bases on the Trojan planets. Four weeks later, at the rendezvous just within the orbit of Mars, twenty-nine great vessels had come together.

The armada of the Astrarchy moved down upon Earth.

Joining the dictator in his chartroom, Brek was puzzled. "Still I don't see the reason for such a show of strength," he said. "Why have you gathered three fourths of your s.p.a.ce forces, to crush a handful of plotters?"

"We have to deal with more than a handful of plotters." Behind the pale mask of the Astrarch's face, Brek could sense a tension of worry.

"Millions of Earthmen have labored for years to prepare for this rebellion. Earth has built a s.p.a.ce fleet."

Brek was astonished. "A fleet?"

"The parts were manufactured secretly, mostly in underground mills," the Astrarch told him. "The ships were a.s.sembled by divers, under the surface of fresh-water lakes. Your old friend, Grimm, is clever and dangerous. We shall have to destroy his fleet, before we can bomb the planet into submission."

Steadily, Brek met the Astrarch's eyes. "How many ships?" he asked.

"Six."

"Then we outnumber them five to one." Brek managed a confident smile.

"Without considering the further advantage of the autosight. It will be no battle at all."

"Perhaps not," said the Astrarch, "but Grimm is an able man. He has invented a new type reaction tube, in some regards superior to our own."

His dark eyes were somber. "It is Earthman against Earthman," he said softly. "And one of you shall perish."

Day after day, the armada dropped Earthward.

The autosight served also as the eyes of the fleet, as well as the fighting brain. In order to give longer base lines for the automatic triangulations, additional achronic-field pick-ups had been installed upon half a dozen ships. Tight achronic beams brought their data to the immense main instrument, on the Warrior Queen. The autosight steered every ship, by achronic beam control, and directed the fire of its guns.

The Warrior Queen led the fleet. The autosight held the other vessels in accurate line behind her, so that only one circular cross section might be visible to the telescopes of Earth.

The rebel planet was still twenty million miles ahead, and fifty hours at normal deceleration, when the autosight discovered the enemy fleet.

Brek Veronar sat at the curving control table.

Behind him, in the dim-lit vastness of the armored room, bulked the main instrument. Banked thousands of green-painted cases--the intricate cells of the mechanical brain--whirred with geodesic a.n.a.lyzers and integrators. The achronic field pick-ups--sense organs of the brain--were housed in insignificant black boxes. And the web of achronic transmission beams--instantaneous, ultrashort, nonelectromagnetic waves of the subelectronic order--the nerve fibers that joined the busy cells--was quite invisible.

Before Brek stood the twenty-foot cube of the stereoscreen, through which the brain communicated its findings. The cube was black, now, with the crystal blackness of s.p.a.ce. Earth, in it, made a long misty crescent of wavering crimson splendor. The Moon was a smaller scimitar, blue with the dazzle of its artificial atmosphere.

Brek touched intricate controls. The Moon slipped out of the cube.

Earth grew--and turned. So far had the autosight conquered time and s.p.a.ce. It showed the planet's Sunward side.

Earth filled the cube, incredibly real. The vast white disk of one lowpressure area lay upon the Pacific's glinting blue. Another, blotting out the winter brown of North America, reached to the bright gray cap of the arctic.

Softly, in the dim room, a gong clanged. Numerals of white fire flickered against the image in the cube. An arrow of red flame pointed. At its point was a tiny fleck of black.

The gong throbbed again, and another black mote came up out of the clouds.

A third followed. Presently there were six. Watching, Brek Veronar felt a little stir of involuntary pride, a dim numbness of regret.

Those six vessels were the mighty children of Tony Grimm and Elora, the fighting strength of Earth. Brek felt an aching tenseness in his throat, and tears stung his eyes. It was too bad that they had to be destroyed.

Tony would be aboard one of those ships. Brek wondered how he would look, after twenty years. Did his freckles still show? Had he grown stout? Did concentration still plow little furrows between his blue eyes?

Elora--would she be with him? Brek knew she would. His mind saw the Martian girl, slim and vivid and intense as ever. He tried to thrust away the image. Time must have changed her. Probably she looked worn from the years of toil and danger; her dark eyes must have lost their sparkle.

Brek had to forget that those six little blots represented the lives of Tony and Elora, and the independence of the Earth. They were only six little lumps of matter, six targets for the autosight.

He watched them, rising, swinging around the huge, luminous curve of the planet. They were only six mathematical points, tracing world lines through the continuum, making a geodesic pattern for the a.n.a.lyzers to unravel and the integrators to project against the future The gong throbbed again.

Tense with abrupt apprehension, Brek caught up a telephone.

"Give me the Astrarch.... An urgent report.... No, the admiral won't do....

Gorro, the autosight has picked up the Earth fleet ... Yes, only six ships, just taking off from the Sunward face. But there is one alarming thing."

Brek Veronar was hoa.r.s.e, breathless. "Already, behind the planet, they have formed a cruising line. The axis extends exactly in our direction. That means that they know our precise position, before they have come into telescopic view. That suggests that Tony Grimm has invented an autosight of his own!"

Strained hours dragged by. The Astrarch's fleet decelerated, to circle and bombard the mother world, after the battle was done. The Earth ships came out at full normal acceleration.

"They must stop," the Astrarch said. "That is our advantage. If they go by us at any great velocity, we'll have the planet bombed into submission before they can return. They must turn back--and then we'll pick them off."

Puzzlingly, however, the Earth fleet kept up acceleration, and a slow apprehension grew in the heart of Brek Veronar. There was but one explanation. The Earthmen were staking the life of their planet on one brief encounter.

As if certain of victory!

The hour of battle neared. Tight achronic beams relayed telephoned orders from the Astrarch's chartroom, and the fleet deployed into battle formation--into the shape of an immense shallow bowl, so that every possible gun could be trained upon the enemy.

The hour--and the instant!

Startling in the huge dim s.p.a.ce that housed the autosight, crackling out above the whirring of the achron-integrator, the speaker that was the great brain's voice counted off the minutes.

"Minus four--" The autosight was set, the pick-ups tuned, the director relays tested, a thousand details checked. Behind the control table, Brek Veronar tried to relax. His part was done.

A s.p.a.ce battle was a conflict of machines. Human beings were too puny, too slow, even to comprehend the play of the t.i.tanic forces they had set loose.

Brek tried to remember that he was the autosight's inventor; he fought an oppression of helpless dread.

"Minus three--" Sodium bombs filled the void ahead with vast silver plumes and streamers--for the autosight removed the need of telescopic eyes, and enabled ships to fight from deep smoke screens.

"Minus two--" The two fleets came together at a relative velocity of twelve hundred thousand miles an hour. Maximum useful range of twenty-inch guns, even with the autosight, was only twenty thousand miles in free s.p.a.ce.

Which meant, Brek realized, that the battle could last just two minutes.