Hell's Gate

stairs.
        He looked into the top floor's corridor. There was no traffic. He stepped out and ran lightly and, he hoped, silently, to the extreme right end of the corridor. The building seemed about two blocks long, so the run was a feat performed not totally without damaged nerves. He expected any moment to run head on into a group of vacii, to be carried down by their long arms and splayed feet But he reached the end and stopped, panting. Quickly, he removed his rucksack from his back, took out one of the many finger-sized bombs the computer had supplied.
        The plan called for the planting of dozens of these weapons in various parts of the structure, each a thing of nuclear capacity. The vacii built to withstand a nuclear blast, but dozens erupting in their midst would be more than the building could absorb. This would more than likely not stop the vacii invasion of their worldline, only delay it. But if the vacii managed to push through again, the men of the future who had sent Salsbury back to destroy the installation would send back yet another android to bring down the next installation. It would be tit-for-tat for a while, though the men of Salsbury's probability's future hoped to discourage the vacii in the end. It was a small hope, but the only one.
        He kept hoping he could think of something better.
        He jammed the pronged end of the white bomb into the plaster-like material of the wall. It blended almost perfectly. As hastily as possible, he planted a second one at the other end of the top floor. Then he ran back to the stairwell and went down a floor. Only fourteen more levels to go.
        He knew he could not hope to accomplish all that without meeting a vacii.
        Unfortunately, the trouble came early. On the eleventh floor, with eight bombs planted, he encountered his first opposition.

CHAPTER 14
        
        As before, Salsbury heard them coming before he saw them. Their screeching voices grated on his nerves so harshly that, in seconds, he felt like raw, quivering meat. He had planted the second explosives package on that floor, and was making for the stairs like a cockroach on his way to a crack in the baseboard when he heard them coming up the stairs. He skittered backwards, out of the stairs and into the hall, up against the cool white wall, trying to look like an irregular hunk of plaster.
        He could wait there in hopes the vacii would pass this floor by, but what if their destination was this floor? A rather nasty scene would ensue, surely, if they found their temple had been violated by a human being with a gas pellet pistol in his hand and a rucksack full of microminiaturized bombs on his back.
        The seconds sped past while he fought his own terror to reach a course of action. He wondered, caustically, where the speed of mental processes the 810-40.04 had spoke so much about was. Finally, when the voices were so loud they seemed to be coming from inside his head, he back pedaled to a door on his left, slipped his hand in the groove and waited. If the vacii continued up the stairs, there was no problem. He would be in the clear, free. But if they got off at this floor, he could be into this room before they saw him. But he didn't want to open the door and risk finding out what was on the other side unless he had to. He had to.
        He caught a glimpse of a blue robe and the darker, overlaid harness of a vacii costume. One withered lizardy leg appeared at the edge of the door from the stairs. They were coming to this floor despite his prayers. Sliding the door open, he went into a lighted room that was much like other rooms he had seen thus far, and slid the portal shut behind.
        “ Zee gee' sa tiss ga',” a vacii said, coming from behind a desklike piece of furniture.
        Salsbury decided the words did not require an answer, but were some sort of exclamation. “Just come to check the air conditioning,” he said.
        “ Scee-ga-tag!” the vacii said, alarmed.
        But Salsbury had taken its attention away from the hand that held the pistol at his side, gained a moment to bring the gun up unnoticed. He fired, forgetting the weapon was still on a machine gun basis, and scattered the beast into a dozen, hideous pieces.
        Just then there was a noise behind, the door slid open on its runners.
        He danced across the floor, came against the desk, crouched and ready, perspiration flooding down his neck,