Where rigid cylinders of gleaming metal had been, a few jagged teeth of brown corruption lay in a circle. The pistons were no better, though their thickness had preserved more of their original shape despite the inroads of age, so they could be recognized for what they were--had been. The central shaft was a long mound of flaking dust on the floor between the path of the pistons, and the wall-sized mass of the filters--woven of metal and powerful synthetic fibers--crumbled beneath the pressure of his finger. He sought and found the ponderous casing in which the engine-empowering radioactive element had lain, and its thick walls tore away like wood pulp in his hands. The element, when he found it, was already become cold grey lead. And it had had a half-life of centuries.... Rik crumpled slowly to the floor, shutting his eyes, trying not to think of the eons which must have passed while they all lay sleeping the pseudodeath in the vaults. What might the world have become in the interim! * * * * * A current of cool air suddenly touched his face. His head came up instantly, his eyes seeking the source. A feathery motion of torn edges in the filter showed him that it came through the gap he had torn there. Rik sprang to his feet then, leaped at the filter and tore out chunks by the armful, letting the pulverized material float in spinning clouds of dust motes behind him. The air grew stronger, came faster, as he ripped away the corruption, and then he could see the tunnel beyond. Gasping at the effort--how long since he had eaten?--he staggered back from the opening then back up the stairs into the chamber of the elders. Now that his nostrils had been stimulated by the clean air the smell of corruption was violently repelling; but he held his breath and ran to the gap in the tumbled rock about the archway, and squeezed his way into the area of subsidiary vaults. Without the pump in operation, the air could not circulate to this point, but he hoped to drag some of his companions down to the torn filter and revive them--then, with their help, bring the others. It would be all right. They would be saved, as planned. He regretted the loss of the elders. But no matter. They were but the rulers. He and the others were the chemists, the scientists, the engineers. New elderships could be created when they had become settled again, and could rebuild their civilization. He went to Zina's slab first. She would not be as much help as some of the others, but Zina and he were too close for him to delay her revival any longer. Life was not worth having without Zina. He carried her out of the vault, through the gap and thick miasma of corruption, then down into the pump chamber. Leaving her lying on her back, with the breeze ruffling her hair about her face, Rik went back up for the next person.