A hitch in time

Frederik Pohl

Obviously the man was dying, and there was no chance that he ever would be discovered.

I blessed the carelessness that had caused me to set the space-time dials a little off when I began this journey to the distant past. I had come to this barbaric era in the proper time, indeed, but millions of miles removed from it in space. It had been only after an annoying search that I had discovered Earth, jetted toward it in my space-drive suit and had come down out of the skies to land on this tiny, deserted island in the middle of an empty sea.

But it was incredible luck that had brought me there. For I had found exactly what I needed-a man who would give me information, clothing and an identity-and then die, and obliterate the record of my interference with the course of events!

I, Thom Ra, walked toward him. Feeble though he was, he opened his eyes and stared at me.

"Thank Heaven!" he whispered, in the thick, hideous language of that era. "I couldn't have lasted much longer if you hadn't found me." He fell back and smiled at me with heartfelt gratitude, and for a moment I felt a wild, fleeting impulse to help him, to save his life. But of course, I dared not interfere. For that would change the shape of the future, and that meant destruction for me....

When I blasted off from the island, a little later, he was dead, and I was wearing his uniform-and his name.

He gave me information before he died, and I had no trouble locating the spot I wanted. I waited till dark before landing a few hundred yards from the war-dome. Then I hid my space-drive suit in a cluster of ancient trees, and walked into the building that housed the most murderous weapon of all time.

The sentry challenged me, of course, but I was ready for him. After a quick look at my stolen credentials he sheathed his ray pistol.

"Pass, sir," he said, and I walked in, no longer as Thom Ra, but identified as a Captain San Requa of the Intelligence Service.

At once I saw the atom-rocket. It was on the other side of the great chamber, nestled in a wheeled cradle, ready to be rolled out to the blast-off point. Hurrying technicians swarmed about it with last-minute checks. I walked over, saluted the officer who was supervising and began to witness events which I had crossed so tremendous a span of years to observe.

The atom-rocket was a long, silvery torpedo, a cluster of tubes at the rear, a snub-nosed warhead at the front. A panel in the side of it was open, and technicians were setting dials according to the figures read off by a white-haired old officer with the insignia of a general on his collar.

I listened in awe and reverence, straining to note and remember everything that occurred. To think that I was actually present at the climactic moment of the legendary War of Annihilation! It was the most thrilling moment of my life. Almost I forgot to curse Master Lys and his duplicity as I watched.

Almost-but not quite. For the thing was too fresh in my mind, and I was aware that I was still in danger.

It had begun with a routine notice that my preparatory work had been approved, and that I was authorized to enter a theme in ortho-history for my final Citizenship Ratings. The theme, I saw with a sinking heart, was the War of Annihilation.

I had hurried to Master Lys, my instructor, sure that there was an error.

"Master, you give me an impossible task," I had said. "The theme regulations are that I must make a 'real and complete contribution to human knowledge.' But how can I? We have so pitifully few records of the War of Annihilation-all of them have been studied, and analyzed, and worked over for thousands of years. There is no way for me to add to what has been written already!"

He cackled at me in his insufferable Tri-Alpha way.

"There is a way," he mumbled, peeping at me out of his rheumy old eyes.

It took me a moment to realize what he meant.

"The time-belts!" And Master Lys nodded.

Well, I argued with him, of course. The time-belts were too dangerous; not one time-traveler in ten returned from the past, even when their projects were as recent as a hundred years ago. And the farther into the past one ventured, the more certain it became that return would be impossible.

For although the mechanism of the time-belts could be trusted and there was no physical menace that the conductor-screens or the katonator-guns could not cope with, there was the ever-present danger of Fan-Shaped Time itself.

It was the First Law of Chronistics: Our era is the product of everything that occurred in the past. Should anything in the past be changed, our age would also be changed. Oh, it would continue to exist, but in a parallel branch of time-and there was no way of passing from one branch to another. And if a traveler into the past should interfere in the course of events, he would be bound to the new time-stream his actions created, and the unlucky traveler would never be able to return.

The branches of Fan-Shaped time could never be retraced. The man who interfered with the space-time matrix, displacing even a comma in the great scroll of time, would be cut off from his origin forever.

The danger was too great. I refused to accept the assignment, even though I knew it would mean I could never rise to the status of Tri-Alpha citizenship which was otherwise my right.

But then I heard about Elren-lovely, adored Elren Dri-and I could no longer refuse.

For Elren's Mating Indices were posted, and she was a Tri-Alpha herself! Then I understood what had been in Master Lys' mind when he set that impossible task for me. For I knew that the gnarled, worm-eaten old wreck had dared to covet my Elren! Loving me, she could never be his. But with me out of the way he might have a chance.

I accepted the assignment. Master Lys secured a time-belt for me-he was willing enough to help at my execution-and I began my perilous journey through time.

I came back to my surroundings with a start. Something was wrong!

Subconsciously I had been studying the atom-rocket, and now I was jolted out of my reveries as I realized that it did not look as it should have.

The ortho-history books were clear on one fact: Venus had been destroyed in the War of Annihilation by means of a hydrogen-chain reaction, the most deadly atom blast known. Atoms of hydrogen, under the influence of gamma-particle bombardment, coalesced to form atoms of helium-and all the incalculable power represented by the odd fraction of mass left over was released in the form of free energy.

But the atom-rocket before me seemed to be nothing more than a simple nuclear-fission affair! Where were the photon-exciters? The gamma-ray bombardment equipment?

Of course, even a fission bomb could do a good deal of local damage, as shown in the first atom-bombed cities during the Little Wars of the early Twentieth Century. But, unless our nuclear science was in error, it could not set off a chain reaction of the type that had destroyed the Venusian colonies. Was I in the wrong place?

Alarmed, I shoved my way closer to the rocket, staring at it. It was a crude, primitive affair, of course, and it was hard for me to identify its parts. I examined it with frantic curiosity-and abruptly I found myself in peril!

One of the technicians I had pushed aside was staring at me, eyes filled with suspicion. I caught his gaze and cursed myself for having acted so rashly. Desperately I strove to think of a way to allay his suspicions, but it was too late.

"What are you doing?" the technician demanded. "Who are you?"

I tried to conciliate him.

"Captain San Requa's my name," I said, using the name on the stolen identity papers. "I am-" But I got no farther than that. My accent gave me away.

"He's a spy!" roared the technician. "Help!" And a dozen ray-pistols flashed out of their holsters as the men around us were galvanized into action.

I lost my head. Terrified, I grabbed for the safety belt concealed beneath my stolen tunic, touched the button that controlled my conductor screen. The screen shimmered into instant life, and not a moment too soon. Rays from the weapons pointed at me flashed from all sides, sparked against the opalescent curtain of the screen and were dissipated.

I was safe-but only for an instant.

For I had made my second great mistake. I was too close to the atom-rocket. My conductor screen grazed the warhead itself!

Its energies surged through the unstable elements in the warhead; a warning bell sprang into clamorous life. The group around me froze in their tracks, mouths open, faces mirroring fright and disbelief-and the frightful power of the strained atoms within the warhead began to grind toward nuclear fission!

There was only one thing to do, and a poor choice it was! But in a moment the warhead would explode, and of me and my mission, and the whole future of Earth, nothing would be left but a puff of fiery vapor.

Quickly I dropped the shield of my conductor screen. Trusting that my luck would hold, and the men around me would be too dazed to fire their weapons again, I drew my katonator, set it at drain, focused it on the atomic warhead.

Drawing my katonator, I focused the twin violet beams on the warhead of the atomic bomb.

The twin violet beams sprang out and impinged on the silvery metal, pierced it and sucked the heart from the seething mass of erupting matter within. Blinding energies were drawn from those toppling atomic structures, surging through the carrier-beam of the katonator into the photon-pack cartridges at my waist. I had an instant's fear as I wondered if the...