It all felt pleasingly familiar. He had always thought that he hated army life and it came as something of a shock to him when he discovered just how comfortable it felt to be back in.
He had re-enlisted with the rank of captain. The promotion had come as a result of his last assignment, an historical adjustment in 12th-century England. When it was all over, he had vowed that he would never go through anything like that again.
An adjustment was nothing like a standard mission. It wasn't like being infiltrated into the ranks of soldiers of the past, fighting side by side with them to help determine the outcome of a war being fought on paper in the 27th century. In an adjustment, temporal continuity had been disturbed. What Dr. Albrecht Mensinger had referred to as a "ripple" had been set into motion and there was a threat of serious temporal contamination. The timeflow was endangered and the timestream could be split. That, the greatest of all possible temporal disasters, had to be prevented at all costs.
The timestream split, Mensinger's solution to the grandfather paradox, had been the focus of the Temporal SALT talks of 2515, when the treaty that governed the fighting of the time wars had been hammered out and all power given to the extranational Referee Corps, who acted as the managers and final arbiters of all temporal conflicts.
The past was absolute. It had happened, it had been experienced, it could not be changed. Prior to the treaty, it had been believed that the inertia of the timeflow would prevent all but the most limited and insignificant temporal disruptions. Dr. Mensinger had proved otherwise, using the grandfather paradox for his model.
The riddle posed the question of what would happen if a man were to travel back into the past, to a point in time before his grandfather procreated a son. If that time traveler then killed his own grandfather, then his father would not be born, which meant that he would not be born. Hence, the grandfather paradox. If the time traveler had never been born, then how could he have traveled back through time to kill his grandfather?
Mensinger had shown how the inertia of the timeflow would compensate for such a paradox. At the instant of the grandfather's demise, the timestream would be split, creating two timelines running parallel to one another. In one timeline, the absolute past of the time traveler would be preserved. In the other, his action would be taken into account. Since there had to be an absolute past for the time traveler in which he had not yet interfered with the continuity of time, he would find himself in that second timeline, which he had created by his action.
The split would result in a universal duplication of matter. Everything that had existed in the past, prior to the split, would now exist in that second timeline, as well. Events in that timeline would proceed, affected by the action taken by the time traveler. Mensinger had stated that it might be possible to deal with a split timestream by sending someone back into the past to a point in time prior to the split. Then, theoretically, the time traveler could be prevented from murdering his grandfather. However, in the event of such a split, the split would have had to have occurred before it could be prevented from occurring. Anyone going back in time to prevent the time traveler from murdering his grandfather could be coming from a future in which that grandfather had already been murdered by his grandson.
Mensinger had discovered, to his chagrin, that split timelines would eventually rejoin. If the timelines had already rejoined at the point that those going back into the past to prevent the murder of the grandfather departed, then their actions in preventing the split would not, in fact, be preventative. Rather, they would be in the nature of changing something which had already occurred before it occurred. This raised the possibility of yet another split. If not, then it meant the eradication of an entire timeline, which raised equally frightening possibilities. It would mean the genocide of everyone who existed in that timeline created by the murder of the grandfather. Not only would this be mass murder on an unimaginable scale, it would also mean dire consequences for the future, the events of which could have been dictated by actions taken in that second timeline.
Mensinger had been awarded the coveted Benford Prize for his research, but he had frightened himself so badly that he had discontinued his experiments. He had called for an immediate cessation of temporal warfare and for the strictest monitoring of time travel. He claimed that the dubious advantages of waging war within the conflicts of the past in order to spare the present from the grim realities of warfare were far outweighed by the dangers inherent in the system. No one had disagreed with him, yet the time wars continued. In order for temporal warfare to become a thing of the past, someone would have to stop it first. And not one nation had been willing to refrain from time travel out of fear that other nations would continue the practice, using time as a weapon against them.
The adjustment to which Lucas Priest had been assigned had represented the closest potential for a timestream split in the history of the time wars. The mission had been successfully completed and the continuity of time had been preserved, but it had cost the lives of half of Priest's unit. Only Lucas Priest and Finn Delaney had returned alive, and not even they would have survived had it not been for the intervention of a Temporal Corps deserter by the name of Reese Hunter.
Lucas had often thought about Reese Hunter since then. Until he had met Hunter, he had not been aware of the existence of a temporal underground, a loosely organized network of deserters from the Temporal Corps. These were men and women whose cerebral implants had either been damaged or removed, so that they could not be traced. Most of them had chosen to defect to the time periods in which they had deserted, but a few, like Hunter, possessed stolen chrono-plates whose tracer functions had been bypassed. These people had achieved the ultimate in freedom. All of time was at their beck and call.
There was but one limitation placed upon the existence of the members of the underground. A split or even a minor disruption in the timeflow could affect their very existence, so in that respect, even though they were deserters, they were still bound by the General Orders that defined what actions a soldier of the Temporal Corps could take in Minus Time.
Lucas often wondered how many people in the past were actually people from the future. It was frightening to realize just how delicate and fragile the timestream had become. If the ordinary citizen had any idea how precarious the balance was and how easily it could be tipped, he would become a raving paranoid. It was within this system that Lucas had to function. It was to this system that he had returned, by choice.
It made him wonder about his own stability. It also made him wonder if there had really been a choice for him at all.
They had, predictably, assigned him to the Time Commandos as a result of that last mission. His commission was in Major Forrester's First Division, an elite unit assembled for the express purpose of dealing with threats to temporal continuity. Being an officer in the First Division entitled him to certain perks, such as free transportation anywhere in Plus Time and luxurious billeting in the bachelor officer's quarters at TAC-HQ. But hand in hand with special privileges went special risks. Though he was in a higher pay scale now, the odds of his not living to collect his pay had gone up correspondingly. Standard missions had scared him half to death before and now his assignments would almost certainly all be adjustments. It was a far more lethal proposition now.
"So how come I'm not shaking like a leaf?" Lucas mumbled.
>
"Sir?" The driver turned around briefly.
"Nothing, Corporal. Just thinking out loud." Lucas finished his cigarette and threw the butt away. Leaning back against the seat again, he sighed and closed his eyes. Oh, well, he thought, at least I won't be bored.
The shuttle dropped him off in front of the headquarters building of the Temporal Army Command. As he rode the lift tube up to TAC-HQ, he watched the bustle of activity in the plaza far below. He carried no luggage, nothing in the way of personal possessions. The few material possessions he had accumulated during his brief return to civilian life had all been left behind in his conapt, a bequest to some future tenant. From now on, his life would once again consist of necessities picked up in the PX, issued field kits, and following orders. Paradoxically, he felt marvelously free.
It felt strange to be saluted in the corridors. As a noncom, Lucas had never insisted on military protocol, or as most soldiers called it, "mickey mouse." It was an age-old expression and no one seemed to know where it had come from. Lucas had once queried the data banks on it, only to discover that the information was classified.
The First Division lounge was a small bar and it was almost empty, so Lucas spotted Delaney at once. He was sitting all alone at a table by a window, hunched over his drink. He had lost some weight and the thick red hair had been shaved, but as Lucas approached the table, he saw that at least one thing hadn't changed. Delaney still could not hold onto a promotion.
"Well, that commission didn't last long, did it?" Lucas said, eying Finn's armband, emblazoned with the single chevron of a Pfc.
"Priest! Good God!"
Lucas grinned. "That's Captain Priest to you, Mister."
Delaney got to his feet and they shook hands warmly, then hugged, clapping each other on the back. Finn held him at arm's length, his beefy hands squeezing Lucas's biceps.
"You look good, kid," he said. "But I thought you'd mustered out."
"I did. I re-enlisted."
"Whatever happened to that burning desire for the easy civilian life?" said Finn.