was visible, a dull blue-grey at close range, and the surface of it felt just like the central barrier.
He experimented by tossing a handful of sand at it, and the sand reached the wall and disappeared as it went through. The hemispherical shell was a force-field, too, but an opaque one, instead of transparent like the barrier.
He followed it round until he came back to the barrier, and walked back along the barrier to the point from which he’d started.
No sign of water.
Worried now, he started a series of zigzags back and forth between the barrier and the wall, covering the intervening space thoroughly.
No water. Blue sand, blue bushes, and intolerable heat. Nothing else.
It must be his imagination, he told himself, that he was suffering that much from thirst. How long had he been there? Of course, no time at all, according to his own space-time frame. The Entity had told him time stood still out there, while he was here. But his body processes went on here, just the same. According to his body’s reckoning, how long had he been here? Three or four hours, perhaps. Certainly not long enough to be suffering from thirst.
Yet he was suffering from it; his throat was dry and parched. Probably the intense heat was the cause. It was hot , a hundred and thirty Fahrenheit, at a guess. A dry, still heat without the slightest movement of air.
He was limping rather badly and utterly fagged when he finished the futile exploration of his domain. He stared across at the motionless Roller and hoped it was as miserable as he was. The Entity had said the conditions here were equally unfamiliar and uncomfortable for both of them. Maybe the Roller came from a planet where two-hundred-degree heat was the norm; maybe it was freezing while he was roasting. Maybe the air was as much too thick for it as it was too thin for him. For the exertion of his explorations had left him panting. The atmosphere here, he realized, was not much thicker than on Mars.
No water. That meant a deadline, for him at any rate. Unless he could find a way to cross that barrier or to kill his enemy from this side of it, thirst would kill him eventually.
It gave him a feeling of desperate urgency, but he made himself sit down a moment to rest, to think. What was there to do? Nothing, and yet so many things. The several varieties of bushes, for example; they didn’t look promising, but he’d have to examine them for possibilities. And his leg—he’d have to do something about that, even without water to clean it; gather ammunition in the form of rocks; find a rock that would make a good knife.
His leg hurt rather badly now, and he decided that came first. One type of bush had leaves—or things rather similar to leaves. He pulled off a handful of them and decided, after examination, to take a chance on them. He used them to clean off the sand and dirt and caked blood, then made a pad of fresh leaves and tied it over the wound with tendrils from the same bush.
The tendrils proved unexpectedly tough and strong. They were slender and pliable, yet he couldn’t break them at all, and had to saw them off the bush with the sharp edge of blue flint. Some of the thicker ones were over a foot long, and he filed away in his memory, for future reference, the fact that a bunch of the thick ones, tied together, would make a pretty serviceable rope. Maybe he’d be able to think of a use for rope.
Next, he made himself a knife. The blue flint did chip. From a foot-long splinter of it, he fashioned himself a crude but lethal weapon. And of tendrils from the bush, he made himself a rope-belt through which he could thrust the flint knife, to keep it with him all the time and yet have his hands free.
He went back to studying the bushes. There were three other types. One was leafless, dry, brittle, rather like a dried tumbleweed. Another was of soft, crumbly wood, almost like punk. It looked and felt as though it would make excellent tinder for a fire. The third type was