The Invincible hung in space, an empty, airless hull, the largest thing afloat.

Chartered freighters, leaving their ports from distant parts of the Earth, had converged upon her hours before, had unloaded crated apparatus, storing it in the yawning hull. Then they had departed.

Now the sturdy little space-yacht, Comet, was towing the great ship out into space, 500,000 miles beyond the orbit of the Moon. Slowly the hull was being taken farther and farther away from possible discovery.

Work on the installation of the apparatus had started almost as soon as the Comet had first tugged at the ponderous mass. Leaving only a skeleton crew in charge of the Comet, the rest of the selected crew had begun the assembly of the mighty machines which would transform the Invincible into a thing of unimaginable power and speed.

The doors were closed and sealed and the air, already stored in the ship's tanks, was released. The slight acceleration of the Comet's towing served to create artificial weight for easier work, but not enough to handicap the shifting of the heavier pieces of apparatus. An electric cable was run back from the little yacht and the Invincible took her first breath of life.

The work advanced rapidly, for every man was more than a mere engineer or spacebuster. They were a selected crew, the men who had helped to make the name of Gregory Manning famous throughout the Solar System.

First the engines were installed, then the two groups of five massive power plants and the single smaller engine as an auxiliary supply plant for the light, heat, air.

The accumulators of the Comet were drained in a single tremendous surge and the auxiliary generator started. It in turn awoke to life the other power plants, to leave them sleeping, idling, but ready for instant use to develop power such as man never before had dreamed of holding and molding to his will.

Then, with the gigantic tools these engines supplied… tools of pure force and strange space fields… the work was rapidly completed. The power boards were set in place, welded in position by a sudden furious blast of white hot metal and as equally sudden freezing, to be followed by careful heating and recooling till the beryl-steel reached its maximum strength. Over the hull swarmed spacesuited men, using that strange new power, heat-treating the stubborn metal in a manner never before possible.

The generators were charging the atoms of the ship's beryl-steel hide with the same hazy force that had trapped and held the gangster ship in a mighty vise. Thus charged, no material thing could penetrate them. The greatest meteor would be crushed to drifting dust without so much as scarring that wall of mighty force… meteors traveling with a speed and penetrative power that no gun-hurled projectile could ever hope to attain.

Riding under her own power, driven by the concentration of gravitational lines, impregnable to all known forces, containing within her hull the secrets of many strange devices, the Invincible wheeled in space.

* * *

Russell Page lounged in a chair before the control manual of the tele-transport machine. He puffed placidly at his pipe and looked out through the great sweep of the vision panel. Out there was the black of space and the glint of stars, the soft glow of distant Jupiter.

Greg Manning was hunched over the navigation controls, sharp eyes watching the panorama of space.

Russ looked at him and grinned. On Greg's face there was a smile, but about his eyes were lines of alert watchfulness and thought. Greg Manning was in his proper role at the controls of a ship such as the Invincible, a man who never stepped backward from danger, whose spirit hungered for the vast stretches of void that lay between the worlds.

Russ leaned back, blowing smoke toward the high-arched control room ceiling.

They had burned their bridges behind them. The laboratory back in the mountains was destroyed. Locked against any possible attack by a sphere of force until the tele-transport had lifted from it certain items of equipment, it had been melted into a mass of molten metal that formed a pool upon the mountain top, that ran in gushing, fiery ribbons down the mountain side, flowing in gleaming curtains over precipices. It would have been easier to have merely disintegrated in one bursting flash of energy, but that would have torn apart the entire mountain range, overwhelmed and toppled cities hundreds of miles away, dealt Earth a staggering blow.

A skeleton crew had taken the Comet back to Earth and landed it on Greg's estate. Once again the tele-transport had reached out, wrapped its fingers around the men who stepped from the little ship. In less than the flash of a strobe light, they had been snatched back to the Invincible, through a million miles of space, through the very walls of the ship itself. One second they had been on Earth, the next second they were in the control room of the Invincible, grinning, saluting Greg Manning, trotting back to their quarters in the engine rooms.

* * *

Russ stared out at space, puffed at his pipe, considering.

A thousand years ago men had held what they called tournaments. Armored knights rode out into the jousting grounds and broke their lances to prove which was the better man. Today there was to be another tournament. This ship was to be their charger, and the gauntlet had been flung to Spencer Chambers and Interplanetary Power. And all of space was to be the jousting grounds.

This was war. War without trappings, without fanfare, but bitter war upon which depended the future of the Solar System. A war to break the grip of steel that Interplanetary accumulators had gained upon the planets, to shatter the grim dream of empire held by one man, a war for the right to give to the people of the worlds a source of power that would forever unshackle them.

Back in those days, a thousand years ago, men had built a system of government that historians called the feudal system. By this system certain men were called lords or barons and other titles. They held the power of life and death over the men “under” them.

This was what Spencer Chambers was trying to do with the Solar System… what he would do if someone did not stop him.

* * *

Russ bit viciously on his pipe-stem.

The Earth, the Solar System, never could revert to that ancient way of government. The proud people spawned on the Earth, swarming outward to the other planets, must never have to bow their heads as minions to an overlord.

The thrum of power was beating in his brain, the droning, humming power from the engine rooms that would blast, once and forever, the last threat of dictatorship upon any world. The power that would free a people, that would help them on and up and outward to the great destiny that was theirs.

And this had come because, wondering, groping, curiously, he had sought to heat a slender thread of imperm wire within Force Field 348, because another man had listened and had made available his fortune to continue the experiments. Blind luck and human curiosity… perhaps even the madness of a human dream… and from those things had come this great ship, this mighty power, these many bulking pieces of equipment that would perform wonders never guessed at less than a year ago.

Greg Manning swiveled his chair. “Well, Russ, we're ready to begin. Let's get Wrail first."

Russ nodded silently, his mind still half full of fleeting thought. Absent-mindedly he knocked out his pipe and pocketed it, swung around to the manual of the televisor. His fingers reached out and tapped a pattern.

Callisto appeared within the screen, leaped upward at them. Then the surface of the frozen little world seemed to rotate swiftly and a dome appeared.

The televisor dived through the dome, sped through the city, straight for a penthouse apartment.

Ben Wrail sat slumped in a chair. A newspaper was crumpled at his feet. In his lap lay a mangled dead cigar.

"Greg!” yelled Russ. “Greg, there's something wrong!"

Greg leaped forward, stared at the screen. Russ heard his smothered cry of rage.

In Wrail's forehead was a tiny, neatly drilled hole from which a single drop of blood oozed.

"Murdered!” exclaimed Russ.

"Yes, murdered,” said Greg, and there was a sudden calmness in his voice.

Russ grasped the televisor control. Ranthoor's streets ran beneath them, curiously silent and deserted. Here and there lay bodies. A few shop windows were smashed. But the only living that stirred was a dog that slunk across the street and into the shadows of an alley.

Swiftly the televisor swung along the streets. Straight into the screen clanked a marching detail of government police, herding before them a half dozen prisoners. The men had their hands bound behind their backs, but they walked with heads held high.

"Revolution,” gasped Russ.

"Not a revolution. A purge. Stutsman is clearing the city of all who might be dangerous to him This will be happening on every other planet where Chambers holds control."

Perspiration ran down Russ's forehead and dripped into his eyes as he manipulated the controls.

"Stutsman is striking first,” said Greg, calmly… far too calmly. “He's consolidating his position, possibly on the pretense that plots have been discovered."

A few buildings were bombed. A line of bodies were crumpled at the foot of a steel wall, marking the spot where men had been lined up and mowed down with one sweeping blast from a heater.

Russ turned the television controls. “Let's see about Venus and Mars."

The scenes in Ranthoor were duplicated in Sandebar on Mars, in New Chicago, the capital of Venus. Everywhere Stutsman had struck… everywhere the purge was wiping out in blood every person who might revolt against the Chambers-dictated governments. Throughout the Solar System violence was on the march, iron-shod boots trampling the rights of free men to tighten the grip of Interplanetary.

IN the control room of the Invincible the two men stared at one another.

"There's one man we need,” said Greg. “One man, if he's still alive, and I think he is."

"Who is that?” asked Russ.

"John Moore Mallory,” said Greg.

"Where is he?"

"I don't know. He was imprisoned in Ranthoor, but Stutsman transferred him some place else. Possibly to one of the prison fleet.” “If we had the records of the Callisto prison,” suggested Russ, “we could find out."

"If we had the records…"

"We'll get them!” Russ said.

He swung back to the keyboard again.

A moment later the administration offices of the prison were on the screen.

The two men searched the vision plate.

"The records are most likely in that vault,” said Russ. “And the vault is locked."

"Don't worry about the lock,” snapped Greg. “Just bring the whole damn thing here-vault and records and all."

Russ nodded grimly. His thumb tripped the tele-transport control and from the engine rooms came a drone of power. In Ranthoor Prison, great bands of force wrapped themselves around the vault, clutching it, enfolding it within a sphere of power. Back in the Invincible the engines screamed and the vault was ripped out of the solid steel wall as easily as a man might rip a button from his shirt.