Snow had fallen in the morning but now the sky was clear and Ruy, with a glance at the frosty stars and a sharp twist of his foot as he ground out a cigarette, stepped out quickly. It was axiomatic. What had to be done, had to be done. A forged pass, with 48 hours of alleged validity gleaming brightly in red letters under the plastic overlaminate was better than no pass. And an outdated pass would wipe away a week's work in the underground.

The sharp, massive gray outline of the Pentagon loomed before him, dark and foreboding against the sky. The brightly lighted entrance through which he must gain admittance resembled the glowing peep-hole into the inferno of an atomic drive.

Ruy's stomach hardened, then exploded in a surge of bitter, stringent gastric juices as the MP glanced at his pass, scrutinized his face, and then turned his attention toward others coming through the entrance.

Ruy wanted to run and hide. His dark blue uniform seemed to shrink tighter and tighter. The misfit must be apparent from the back. The silvery commander's insignia on his jacket weighed heavily at his chest and at his heart. He wished desperately for one fleeting, but excruciating, moment that he were back on his ship, in his own uniform, at the control panel of his computer.

He started off to the right in a seeming trance. The first step had been taken. His many hours of thought, study and planning would carry him from here.

This was the only way. He had repeated the fact over and over. It was an ugly business, but had to be done. Five years of war was enough. Man was on his knees before the invaders from outer space; but they in turn had been too long from home and were near the breaking point. A continued drain would mean defeat for both sides. Ruy could turn the tide, but very probably his life would be the minimum sacrifice.

He had decided his fate long before he left the decks of his ship. Only the belligerent pride of statesmen, and the steadfast belief in the infallability of their computers, kept the two great battle fleets drawn in null position against each other. The computers, perhaps, deserved such ultimate confidence—in theory. They always predicted optimum maneuver envelopes, always predicted mobilization rates to develop force fields designed to offset those of the enemy. And they always kept battle losses to a minimum—merely dribbling away the resources of the solar system. Yet in five years of such optimum maneuvering, not a single battle had been won.

Two doors gave way before Ruy's pocket vibrator, the lock tumblers slipping and turning freely in a mad frenzy to escape the resonating hum. A short, windowless corridor lay before him, broken only by a massive door at the other end. Beyond that door lay Ruy's objective.

The guard never had time to do more than note Ruy's presence in this sanctum sanctorum. The needle thin spray of a paralyzing drug made his body feel stiff, unmanageable, and peculiarly buoyant, as though he were being hurled through space. His thoughts became blurred and then after a blinding flash, complete oblivion set in.

The two officers seated at the control panels of the master computer experienced similar depression of their cardiovascular systems and medullae.

Small thermite igniters pressed against the door lock and hinges fused the steel door to its frame.

With the smell of scorched paint still stinging his nostrils, Ruy seated himself at the control panel, dabbed his left wrist with stringent antiseptic, gripped his hand into a fist, and plunged the silver probes deep into the nerves of his wrist.

Glancing through the observation window into the battle plotting room below, he studied the positions of the fleets as they appeared on the large wall diagram of the solar system.

Disregarding the distraction offered by the moving figures of the few officers and technicians on duty by the map, he fixed the positions of the fleets into his mind. He would have need for a clear visual picture until he adapted to the mental images the computer would feed into his brain. He worked with furious haste, yet each step was meticulously precise—everything depended on his grasping the reins of battle from the computer and successfully twisting its authority to his own purposes.

Grasping the viewing switch, he threw it on. Pinpoints of light flared deep within his brain and seemed to blot his vision. Closing his eyes, his brain fought for perspective. Gradually, it focused and perceived the solar system, resplendent with sun, planets, moons, and men of war. Enveloping each ship were lines of force, scintillating sharp and hard; forming cosmic vortexes as the lesser computers on board followed the master's directives and distorted the ether around the ships, seeking to build a pattern to penetrate the opposing fields and engulf the enemy men of war.

A moment, and the game was on. Ruy grasped the "Manual" switch before him, pulled hard, and dropped his hands to the keyboard before him.

The General, who was known in military circles as a good Joe, but a stickler for the theory of war, relaxed languidly at his desk in the small office off the Battle Room. The other officers on duty milled around the plotting board within his eyesight awaiting the end of the evening shift.

It was strange and new to relax on the job after so many years of fleet duty. But staff duty to the master computer was good, politically. He was getting along in years, and a few more contacts here might mean a separate fleet command of his own, perhaps in pursuit of the invader, if the computers could ever break the deadlock.

Suddenly, the sweet reverie of the General was snapped like a tight tension cable. A gong on the wall clanged rapidly three times and a red flashing light next to the gong told him what his ears refused to believe. The computer had been switched to manual. He had received no such instructions. In fact, the computer hadn't been on manual since the war started.

"Captain, who ordered manual control?" he barked as he sprang to the doorway of the Battle Room.

"I don't know, Sir," stammered the Captain. His manner and bearing were those of a man who had just been faced with a problem of cataclysmic proportions.

"Well check with the control room—on the double—before our fleet gets out of defensive position." His parade ground roar snapped the Captain out of the catelepsy which had enveloped him and sent him scurrying into the corridor.

An almost hysterical shout whirled the General back to the plotting board.

"Sir, our fleet is attacking—attacking!"

"What? Where?" asked the General, his eyes darting over the board in a frantic effort to orient himself.

"Here, Sir, see. The positions are changing gradually in an unusual pattern. A patrol ship, a destroyer, and a cruiser have all gone right into the enemy vortex field," analyzed the Major.

"Yes, I see—But with the enemy concentrating his ships orthogonally—he'll build a vortex that will disintegrate each and every ship of ours near the vortex," said the General, his mind coming up to full battle speed as it grasped the situation. "My God! Can't they see that they're going to certain death?"

A gong sounded in a muffled sort of way in the plotting room below Ruy, as a gentle buzz told him that the computer had relinquished control.

His fingers began to play rapidly over the keys. Swift orders of strategy were transmitted through steel conduits deep into the computer vaults of the building. There, the orders were transposed into detailed tactics and beamed throughout the solar system. And as his fingers limbered to the keys, he played a deadly tune, a concerto of death.

The fleet grew alive with a sudden awareness; it seemed to be a thing alive, straining at its bonds in response to the music played into its computers and controls. Suddenly, the fleet sprang forward. A destroyer shot out into the midst of the enemy fleet, launching all of its energy in one tremendous lurch—only to go down in a flaming wreck as the enemy ships swerved and concentrated on it. And a second ship, and then a third ship repeated the frightful maneuver, until the whole heavens were lighted with the flaming novae of berserk atomic drives.

"General, sir," said the Lieutenant, with sweat rolling from his brow as he saluted.

"Yes, Lieutenant," said the General looking away from the battle map of the solar system.

"We can't make any headway against the control room door. Must be solid steel. Whoever got in there must have fused it shut."

"Well, get a welding torch," said the General, his eyes going back to watch the devastation of the fleet. "We've got to get in—get that computer back on automatic. Get explosives, if necessary."

"We've sent for a welding torch already, sir. It'll be here in a few minutes."

"All right. Send someone for hand grenades too. We've got to stop this sabotage before the fleet is annihilated. They're losing ships every minute."

"Sir," interposed the Captain standing nearby, "maybe we can cut off the computer room someway. I know it's a direct conduit, right to the vaults from the control room, but maybe we can cut the conduits and let the ships fall back on their emergency circuits."

"Looks like a possible alternative, Captain, though we'd put the computer out of operation for several days," said the General. "But we're losing our fleet this way."

Seven, eight, nine great men of war went down before the blazing force fields of the enemy, who pounced on every sacrifice offered to it by the computer.

The Lieutenant turned his eyes from the incandescent glare of the thick steel conduit glowing red under the finger of the acetylene torch. "General, its extremely resistant to cutting. I doubt if we can cut through it before they finally get the door and frame cut away up in the control room."

"Keep at it, boy. We've got to get through at the saboteur one way or another. Do the best you can. The boys in the fleet are counting on you. They're going down to certain death while we delay."

With the last terms of the new equations of strategy played into the computer, Ruy sat back, gave a sigh, opened his eyes, and slipped the electrodes from his wrist. His job was almost done. If he could keep the others from this control panel for another half hour, the computer could operate on his equations fully, and the battle would be won.

The first ships from Earth had already gone down in flames, expendable sacrifices to his purpose. But they were not dying in vain. The end result would be—must be—victory.

Wars are fought by strategy, but also by sacrifice. Every general must send troops into battle, must expect to sacrifice to make the enemy commit himself in the desired way, and so make victory possible.

This was what Ruy believed. He believed it deeply, deeply enough to throw aside his career as a rising young theoretical mathematics officer of the fleet and to go over the heads of his unconvinced superiors, with all their unread reports and unanswered recommendations from subordinates, in the only way a man of action could—by taking things into his own hands, and staking his life on the gamble.

The General, eyes riveted to the board, winced with pain as ship after ship roiled the heavens with flaming death. And as he watched, a gradual subtle design became apparent. For every ship he had lost, his ships had taken a similar tally—for each sacrifice, a trap was sprung and a similar toll taken. Computers did not sacrifice, did not send men out to certain death. Therefore a sacrifice was greedily snapped up as a mistake of the enemy. And such greed snapped the trap. One move forced the next, once the bait was taken.

As the theme of the theory formed in the General's mind, he suddenly muttered: "Even exchange will balance a computer's potential—but a series of forced, even-exchanges can distort a fleet's position from optimum.... I never realized it before—an optimum move is not an optimum move—if it's a forced move."

He turned from the board and spoke quietly to the men who stood in hushed groups watching the flaming battle.

"Gentlemen, we are winning a great victory; the war will soon be over."

The door to the computer room toppled outward, frame and all, after several ceaseless hours of cutting. The impact left the hallway of armed men silent and still, like specters in the unreal light from the glowing acetylene torch. Just inside the doorway stood a man, his youth belied by wise and thoughtful eyes, grinding a cigarette under his foot. And as he stepped through the wrecked and twisted door frame not a hand was raised against him.