He must have blasted it from the crust of Mars without help. It was a series of a half-dozen rooms and was no larger than a fair-sized apartment. Smallest of all was the combined sleeping room and kitchen; and there the evidence of months or perhaps years of absence was plainest. The bunk was thick with dust, and food remnants were blackened on unwashed plates. The air, of earthy density, smelled of decay and a strange pungence. The floors and walls were crusted with patches of the tough, bluish growths seen outside. It was suggestive at once of both fungus and moss but was really like neither. It had a pretty color under the lamps, which had certainly been burning for a long time. Ed and Barbara removed their oxygen helmets and began a swift exploration of the premises. The rooms had all the marks of lone bachelor occupancy by a man too fearfully busy with his own deep pursuits to waste time on more than the barest attempts at housekeeping. Apparatus was everywhere. There were even recognizable parts of a helicopter--the one, no doubt, which had brought Prell and his equipment to this refuge. At first they thought that he might since have fallen victim to some violence or accident. And then they found his body in a rectangular, plastic-covered tank, submerged in a cloudy, viscous fluid. It was a standard sort of vat, much used in laboratories in repairing extensive injury and restoring a destroyed body from a personal recording--either in protoplasm or vitaplasm. Near by, there were three similar vats, which, when opened, proved to contain only fluid. Barbara and Ed looked for a long moment at Mitchell Prell's forever young face. It was peaceful in death that was not quite death; for of the latter you could never be sure any longer, unless it was the death of the species. If there were guile behind that gentle face, it did not show. If there were darkness of purpose, or stubborn unwillingness to recognize errors that he had committed in a civilization that tottered as it reached for greatness, it could not be seen. But in this refuge, one fact was plain: Mitchell Prell had gone on with his work in a super-biology. Ed wandered over to a beautiful microscope of a standard make. Its attachments also started out from a familiar design. It was fitted with dozens of special screws and levers. When Ed, and then Barbara, peered into its eye-piece, they found that each of these screws and levers could manipulate a tiny tool, almost too small to see with the naked eye. There were minute cutters, calipers and burnishing wheels. Set up under the microscope there was even what seemed to be a tiny lathe. In fact, there was an entire machine shop on an ultra-miniature scale. And there were tiny, tonglike grasping members, intended to serve--on such a reduced scheme of things--as hands, where the human hand, working directly, would have been hopelessly mountainous.