Nothing else mattered; nothing but Ohm. He made little changes in the robot's construction. Supplied him with springs that permitted a graceful, bounding movement; increased the flexibility of the jaws and the razor sharp metal teeth. He was puzzled by a peculiar stain that seemed to have discolored Ohm's teeth. Since no food passed the robot's lips, Craig could not account for the presence of the stains. On that night, the torment had been prolonged, and once, during it, Ohm seemed to sense Craig's presence and moved toward him with a peculiar half-pleading, half-threatening motion. Excitedly, Craig recorded the deviation. It seemed to mark some sort of turning point in Ohm's development. When the robot succumbed at last to exhaustion, Craig permitted him to enter the hutch, and leaving him there, proceeded to prepare himself for bed. The sessions with Ohm were leaving him more and more worn out and frazzled. Perhaps Beale had been right. A few days' rest would restore his perspective. Of course he would miss Ohm. Never had he experienced so gratifying a relationship. It was much more complete than his domination of his mother had been or his subjection of Sheila. It left him feeling at once weak and god-like. His toilet completed, he went back to Ohm's hutch to put down the wire mesh for the night. Once or twice, he had forgotten it, and the robot's collisions had awakened him early in the morning. As tired as he was, he wanted now to forestall any such disturbance. * * * * * Ohm was not in his hutch. That was an unlooked-for development. Usually after the experiments, he was so depleted he did not stir from the hutch for hours. And yet now he was gone. Half-heartedly, Craig looked for him, but he was overcome suddenly with a terrible drowsiness. After all, did it matter whether Ohm spent the night in the hutch? He'd huddle in some corner of the apartment till morning. Wearily, Craig snapped off all the lights and stumbled into his bedroom. The bedlamp burned brightly in the darkness. He sank down onto the bed. He couldn't remember ever having been so tired. He closed his eyes. Bright red circles spun and whirled. Sleep. He must have sleep. He was dreaming. The little girl, whose kitten had disappeared was pointing an accusing finger at him. He was trying to explain that he hadn't taken her kitten. And then, Sheila was there, and she had a great urgency in her manner. She was warning him. Stains. The stains that he had noticed. Didn't he see? No. He didn't see. His mind spun and whirled. Sounds were a tortured mixture of Sheila's voice, the little girl's sobs, and the faint mechanical grunts which Ohm made. And then, the laboratory collapsed. The walls caved in to the center and the roof dropped down on top of him. It was a terrible pressure on his chest--crushing it. He had to remove that pressure--had to push that crushing weight away--had to get free.