The central structure of the group of buildings was shaped like a great plus-mark, each of its four wings of identical square construction, with long smooth metal sides and top, and with a door at the end giving entrance to a corridor that ran straight through to the chief central laboratory of Dr. Ku Sui. Carse skimmed swiftly, two feet off the glittering metallic soil, towards the end of the nearest wing, where he gently landed. He tried the door giving entrance. It was open. He cautiously floated through into complete darkness. The Hawk was prepared for that. He drew a hand-flash from the belt of his suit, and, standing motionless, his raygun ready in his left hand, he probed the darkness with a long white beam. Spaced evenly along the sides of the corridor were many identical doors, and at the end a larger, heavier door which gave entrance to the central laboratory. He found no life or anything that moved at all, so, methodically, he set about inspecting the side rooms. The doors were all unlocked, and he moved down the line without alarm, like a mechanical giant preceded by a sweeping, nervous flow of light. Such he might from the outside have appeared to be, but the man within himself was more like a cat scenting for danger, all muscles and senses delicately tuned to alertness. Door by door, a cautious and thorough inspection; but he found nothing of danger. All the rooms of that wing were used merely for stores and equipment, and they were quite silent and deserted. When he came at last to its end, Carse knew that the wing was safe. He paused a minute before the laboratory door. He had expected to find it locked, and that he would have to seek other means of entrance; but it was not. By pushing softly against it, it easily gave inward on silent well-oiled hinges. He entered. * * * * * Carse found himself in a place of memories, and they were sharp and painful in his brain as he stood there. Here so much had happened: here death, and even more than death, had been, and was, so near! The high-walled circular room was dimly lit by daylight tubes from above. The damage he, Carse, had wrought when besieged in it, a week before, had all been repaired. The place was deserted--it seemed even desolate--but in Carse's moment of memory it was peopled. There had been the tall, graceful shape in black silk; there the operating table and the frail old man bound on it; there the four other men, white men and gowned in the smocks of surgeons, but whose faces were lifeless and expressionless. Dr. Ku Sui and his four assistant surgeons and his intended victim, Master Scientist Eliot Leithgow....