More days passed, then weeks; but what could he do? He kept on collecting lichen. One of the cryptoendoliths he found was the first species to survive on the Martian surface, the lectern said, and it had been designed by members of the fabled First Hundred. He broke apart some rocks to have a better look, and found bands of the lichen growing in the rocks’ outer centimeter: first a yellow stripe right at the surface, then a blue stripe under that, then a green one. After that discovery he often stopped on his walks to kneel and put his faceplate to colored rocks sticking up out of the firn, marveling at the crusty scales and their intense pale colors— yellows, olives, khaki greens, forest greens, blacks, grays.

One afternoon he drove the pilot fish far to the north of the Beast, and got out to hike around and collect samples. When he returned, he found that the lock door in the side of the pilot fish would not open. “What the hell?” he said aloud.

It had been so long that he had forgotten that something was supposed to happen. The happening had taken the form of some kind of electronic failure, apparently. Assuming that this was the happening, and not . . . something else. He called in over the intercom, and tried every code he knew on the keypad by the lock door, but nothing had any effect. And since he couldn’t get back in, he couldn’t turn on the emergency systems. And his helmet’s intercom had a very limited range— the horizon, in effect— which down here off Pavonis had shrunk to a Martian closeness, only a few kilometers away in all directions. The Beast was well over the horizon, and though he could probably walk to it, there would be a section of the hike where both Beast and pilot fish would be over the horizon, and himself alone in a suit, with a limited air supply. . . .

Suddenly the landscape with its dirty sastrugi took on an alien, ominous cast, dark even in the bright sunshine. “Well, hell;” Art said, thinking hard. He was out here, after all, to get picked up by the underground. Nirgal had said it was going to look like an accident. Of course this was not necessarily that accident, but whether it was or it wasn’t, panic was not going to help. Best to make the working assumption that it was a real problem, and go from there. He could try walking back to the Beast, or he could try getting into the pilot-fish rover.

He was still thinking things over, and typing at the keypad of the lock door like a champion speed-typist, when he was tapped hard on the shoulder. “Aaa!” he shouted, leaping around.