Once, during the hours when Burke and Keller were sitting quite still, Keller reached over and threw a switch. Nothing happened. Everything went on exactly as it had done before. He shook his head. And much later he went to one of the star-image screens. He moved an inconspicuous knob in a special fashion, and the star-image expanded and expanded until what had been a second of arc or less filled all the screen's surface. The effect of an incredibly powerful telescope was obtained by the movement of one control. Keller restored the knob to its original place and the image returned to its former scale. These were the only actions which took place in the instrument-room. In the lower part of the asteroid, not much more occurred. The entrance to the power and storage areas was not hidden. It simply had not been entered. Sandy and Holmes and Pam went gingerly down a corridor with doors on either side, and then down a ramp, and then into huge caverns filled with monstrous metal things. There was no sign of any motion anywhere, but gigantic power-leads led from the machines to massive switchboards, whose switches were thrown by relays operated from somewhere else. Then there were other caverns which must have contained many varieties of stores. There were great cases, broken open and emptied. There were bins with only dust at their bottoms. There were shelves containing things which might have been textiles, but which crumbled at a touch. Some thousands of years in an absolute vacuum would have evaporated any substance giving any degree of flexibility. These objects were useless. There was a great room with a singular hundred-foot-high machine in it, but there was no vibration or sound to indicate that it was in operation. This, Sandy said decisively, was the artificial-gravity generator. She did not know how it worked. It would have been indiscreet to experiment. She led the way through relatively small corridors to areas in which there were very many small compartments. These had been for foodstuffs. But they were empty. They had been emptied when the asteroid was abandoned. Then they came to the crudely fashioned case with the cryptic symbols on its front. "This is the thing Joe mentioned," said Sandy. "They had writing. They'd have to, to be civilized. But this is the only writing we've seen. Why'd they write it?" "To tell somebody something they'd miss, otherwise," Pam said. "Who'd come down here? Why not put it at the ship-lock where people could be expected to come?" Holmes grunted. "Asking questions like that gets nowhere. It's like asking how the garrison was supplied. There's no answer. Or how it left." Sandy said in a surprised voice, as if saying something she hadn't realized she knew. "There were service ships. They serviced the television eyes on the outside, and they drilled at launching missiles, and so on. They were modified fighting ships, made over after ships didn't fight any more." She hesitated, then went on.