Blade noticed that the speed lever was sliding backward and that the machine seemed to be sinking toward the ground. He reached for the lift control and shoved it back to its previous position. Then he pushed the speed control forward again. By the time the machine passed through the cloud of red smoke, it was moving as fast as before.

The temptation to make a run for it was growing in Blade. It was obvious that the red smoke rocket had been some sort of signal to the machine to stop and land. The computer had been doing just that when he overrode it. That override would be a signal to the other machines that something was wrong in this one. Blade wanted to find out what they would do next, and for that he knew he would have to stay around for a while. On the other hand, he had to get away if he wanted to study this machine at leisure and in detail. He was damned if he did and damned if he didn't. He was also a man who hated to turn his back on an opponent, even for the best of reasons.

So he did not speed up. But he did lift the machine until it was some fifty feet up. Then he started zigzagging, making sharp turns at irregular intervals. He was not going to be an easy target, if he had to be one.

A minute passed, a second, then a third. Blade's teeth were locked tight together with the strain of waiting. When were they going to shoot, if they were? Or maybe they weren't? Maybe he had succeeded in overloading whatever tracking computer the other machines might have? Maybe-?

The howl of an incoming rocket sounded from above. This time the burst came off to the right, less than a hundred yards away. Masses of earth and grass flew into the air on top of a vast cloud of gray brown smoke. This time the blast wave in the air snatched at Blade's machine like a terrier grabbing a rat in its jaws.

The machine lurched wildly, tilting far over to the left. If Blade hadn't been strapped in, he would have sailed out of the chair and smashed into the wall hard enough to break every bone in his body. He clutched the control wheel, his knuckles standing out white. Now he knew what weapons the big machines carried. Now it was time to-

Another rocket hit, this time a hundred yards almost directly behind him. The blast practically stood Blade's machine on its nose. By sheer reflex he pulled the control wheel backward. The machine straightened out of its dive just above the grass.

Blade threw a quick glance behind him. For the moment the machines firing at him were invisible behind the smoke from the second burst. Was he invisible to them?

Probably not. Very likely they carried radar or something like it to track him. But neither radar nor the human eye could see over the horizon. If he stayed low as he ran- Before he had completed the thought, his hand was shoving the speed control all the way forward in one smooth motion.

A giant rubbery fist shoved him back hard into the control chair. On the screens the plain suddenly turned flat, featureless, seemingly as bare as a tabletop. The smoke cloud from the second burst shrank as if by magic. The towers of the abandoned city dwindled to toys, sank down toward the horizon, and vanished. In the dim distance behind him, Blade saw a third rocket burst in a third tree of smoke. But he neither heard nor felt anything. Then the last smoke vanished and he was alone in the machine as it raced away over the plain.

How fast was he moving? There was no speed indicator he could read. But from the blur below him, he knew he must be going not much less than four hundred miles an hour.

Four hundred miles an hour, in a machine with the strength and some of the weapons of a tank. The builders of this machine had built something worth studying, no matter how badly they seemed to have maintained it.

And after he had studied the machine, perhaps he should try studying its makers? Blade grinned. That might be a good idea, if he could ever find them. For all he had seen, he might be the only human being alive in this dimension. But it was going to be interesting nonetheless.

Chapter 8

Blade kept the machine low and fast for a while, partly to be sure he was completely out of range, partly to test the machine's power. By the time he slowed down, even the miles-high cloud of smoke rising above the city had long since dropped below the horizon.

Blade slowed down to about two hundred miles an hour and climbed to a hundred feet. He could now see for miles across the plains and there was far less danger of the ground suddenly and disastrously rising to meet him. The machine looked indestructible but probably wasn't. Blade knew he certainly wasn't.

From the position of the sun Blade guessed he must be heading almost due west. An hour later he came to a stop and landed. By that time he knew he must be a good three hundred miles from the city. If anyone was going to chase him, they would almost certainly have done so long since. As far as he could tell, he was alone on the plain.

Blade did not bother deploying the legs, but simply brought the machine down on its metal belly. It rocked back and forth once or twice, then dug itself into the earth with its own weight. Blade unstrapped himself and began examining the machine more carefully.

The first thing he looked for was food and water. He was not particularly hungry. But he was as thirsty as if he had been marooned in a desert for three weeks. Fortunately the first thing to turn up was a water tap lurking under the control panel, complete with plasticlike cups. Blade emptied his cup seven or eight times before he stopped feeling thirsty.

After that Blade scrambled up into the turret and examined the controls for the ray-tube. They were as simply and carefully laid out as the main controls. After a few minutes Blade felt he could hit anything he aimed at with the purple ray. What the ray would do when it hit was still very much a mystery.

In lockers on either side of the hatch Blade found boxes and cans of concentrated food, as well as sets of clothing. The food was just edible, like emergency rations in every dimension. The clothing was obviously combat uniforms of some sort, camouflaged coveralls with heavy padding from throat to groin, and knee-length boots. The belts, packs, and helmets were made of something that looked like leather but weighed a good deal more. When it came to finding an outfit that he could get into comfortably, Blade had his usual struggle. There were times when he couldn't help wishing he was about three inches shorter and thirty pounds lighter.

There were no hand weapons, but there were a couple of businesslike knives on each belt. There was also a long sharp-pointed tool, rather like a short crowbar with a heavy needle on the end. Blade realized that this was probably the tool for opening the hatch from the outside. After pressing the button to release the hatch and climbing outside, a quick test confirmed his guess. Now he could climb in and out of the machine without having to let those grisly tentacles fumble over him.

He turned on the power, lifted the machine into the air, and headed west again.

The sun sank down toward the horizon, swelling and turning from yellow to orange and from orange to red as it did so. Blade began to think about landing for the night. He did not want to push on in the darkness and risk missing something important or suddenly running out of power.

Then on the plain two miles ahead he saw the horsemen.

There were at least twenty of them. Blade's machine was coming at them out of the twilight, so he saw them before they saw him. But when they did see him, they scattered in all directions, as fast as their horses would carry them.

Blade swooped down and examined the fleeing riders on the screens. All the horses were of the same kind-heavy-chested, heavy-rumped, short-legged, shaggy. They looked enormously tough. They also looked like the horses whose skeletons Blade had seen near the city.