would be arriving subsequent to his previous hasty departure, and there would be no possibility of encountering himself, no paradox.
Again the calculations were not terribly difficult because he needed only to work forward from the numbers that the IBM PC had provided him. Though he knew that the time he spent here was not passing in equal measure in the desert of 1989, he was eager to rejoin Laura nevertheless. Even if she had taken the advice of the message in the bottle, even if the future he had seen had been changed and she was still alive, she would have to deal with those SS gunmen, and she would need help.
In forty minutes he had the numbers that he required, and he reprogrammed the gate.
Again he opened the panel on the jaunt recorder and tore the evidence off that spool of paper.
Carrying the Uzi and the pistol, gritting his teeth as the dull throbbing in his half-healed shoulder grew worse, he entered the gate.
Lugging both the Vexxon canister and the Uzi, Laura joined Chris in the narrower tributary off the main channel, about sixty feet from the point at which they had descended into the system. Crouching at the corner formed by the two earth walls, she looked back into the primary arroyo from which she had come.
On the desert above, one of the surviving assassins shoved the dangling corpse off the brink, into the deep gulch, apparently to see if she was still immediately below them and if she would be tricked into opening fire. When there was no fire, the two survivors became bolder. One lay at the brink with a submachine gun, covering the other man while he slid down. Then the first gunman covered the second's descent.
When the second man joined the first, Laura stepped boldly around the corner and squeezed off a two- second burst. Both of her pursuers were so startled by her aggressiveness that they did not return fire but threw themselves toward the deep, vertical erosion channels in the arroyo wall, seeking shelter there as she had sheltered while waiting for the opportunity to shoot them off the top of the cliff. Only one of them made it to cover. She blew the other one away.
She stepped back around the corner, picked up the cylinder of nerve gas, and said to Chris, 'Come on. Let's hustle.'
As they ran along the tributary, seeking yet another branch in the maze, lightning and thunder split the blue sky above. 'Mr. Krieger!' Chris said.
He returned to the desert seven minutes after he had originally departed for his meetings with Churchill and Hitler in 1944, just
Daring to hope that his scheme had worked, Stefan hurried to the arroyo and ran along the brink, searching for someone, anyone, friend or foe. Before long he saw the three dead men on the floor of the channel, thirty feet below.
There would be a fourth. No SS squad would have been composed of only three men. Somewhere in the network of zigzagging arroyos that crossed the desert like a chain of jagged lightning bolts, Laura was still on the run from the last man.
In the arroyo wall Stefan found a vertical channel that appeared to have been used already; he stripped off his book-filled rucksack, slid to the bottom. On the way down, his back scraped against the earth, and hot pain flared in the partly healed exit wound. At the end of the slope, when he stood up, a wave of dizziness washed through him, and bile rose in his throat.
Somewhere in the maze to the east, automatic weapons chattered.
She halted just inside the mouth of a new tributary and signaled Chris to be quiet.
Breathing through her open mouth, she waited for the last killer to turn the corner into the channel that she had just left. Even in the soft soil, his running footsteps were audible.
She leaned out to gun him down. But he was extremely cautious now; he entered low and at a dead run. When her gunfire alerted him to her position, he crossed the channel and hid against the same wall off which her new tributary opened, so she could get a clear shot at him only if she stepped out into the arroyo where he waited.
In fact she tried that, risking his fire, but when she squeezed off a two-second burst, it ended in less than a second. The Uzi spat out its last ten or twelve rounds, then failed her.
Klietmann heard her Uzi go empty. He looked out from the crevice in the arroyo wall where he was sheltering and saw her throw the gun down. She disappeared into the mouth of the tributary where she had been laying for him.
He considered what he had seen in the Buick, up on the desert: a.38 revolver lying on the driver's seat. He assumed that she had not had time to grab it or, in her haste to get that curious canister from the trunk, had forgotten about the handgun.
She'd had two Uzis, both discarded now. Could she have had two handguns — and left only one in the car?
He thought not. Two automatic carbines made sense because they were useful at a distance and in a variety of circumstances. But unless she was an expert marksman, a handgun would be of little use except at close range, where six shots was about all she would need before she either dealt with her assailant or died at his hands. A second revolver would be superfluous.
Which meant that for self-defense she had — what? That canister? It had looked like nothing more than a chemical fire extinguisher.
He went after her.
The new tributary was narrower than the one before it, just as that one had been narrower than the main channel. It was twenty-five feet deep and only ten feet wide at the mouth, growing shallower and half that narrow as it cut a crooked path through the desert floor. In a hundred yards, it funneled to an end.
At the terminus, she looked for a way out. On two sides the cliffs were too steep, soft, and crumbly to be easily climbed, but the wall behind her sloped at a scalable angle and was studded with mesquite that offered handholds. She knew, however, that they would be only halfway up the slope when their pursuer found them; suspended on that high ground, they would make easy targets.
This was where she would have to make her last stand.
Cornered at the bottom of this big, natural ditch, she looked up at the rectangular patch of blue sky and thought they might have been at the bottom of an enormous grave in a cemetery where only giants were buried.
She pushed Chris behind her, into the point of the dead-end arroyo. Ahead of her, she could see forty feet back the way they had come, along the five-foot-wide channel, to the point where it angled to the left. He would appear at that turn within a minute or two.
She dropped to her knees with the canister of Vexxon, intending to strip the safety wire off the manual trigger. But the wire was not merely looped and braided through the trigger; it was repeatedly wound and then sealed with solder. It could not be unwound; it had to be cut, and she had nothing with which to cut it.
Maybe a stone. A sharp-edged stone might wear through the wire if scraped across it often enough.
'Get me a stone,' she said urgently to the boy behind her. 'One with a rough, sharp edge.'
As he searched the soft, flood-carried soil that had washed down from the desert floor, looking for a suitable scrap of slate, she examined the automatic timer on the canister, which provided a second means of releasing the gas. It was a simple device: a rotating dial was calibrated in minutes; if you wanted to set the timer for twenty minutes, you twisted the dial until the 20 was lined up with the red mark on the dial frame; when you pushed the button in the center, the countdown began.
The problem was that the dial could be set for no fewer than five minutes. The gunman would reach them sooner than that.
Nevertheless she twisted the dial to 5 and pushed the button that started it ticking.
'Here, Mom,' Chris said, presenting her with a blade of slate that just might do the job.
Though the timer was ticking, she set to work, frantically sawing at the strong, twined wire that prevented manual release. Every few seconds she looked up to see if the assassin had found them, but the narrow arroyo ahead of them remained deserted.
Stefan followed the footprints in the soft soil that formed the bed of the arroyo. He had no idea how far
