I turned quickly. The form shimmered in the pale Deimoslight that silhouetted it. MS-33. He had followed me here. “What do you want?” I said. “What are you doing here?” “A simple question,” said MS-33. “Tonight you looked very suspicious when you left Argon City. I saw you and followed you here. You may as well know that I have never trusted you. All the old ones were unreliable. That is why you were replaced.” He came in, boldly, without being invited, and looked around. I detected a sneer in his voice as he said, “So this is where you hide.” “I do not hide. I live here, it is true.” “A robot does not live. A robot exists. We newer models do not require shelter like an animal. We are rust-proof and invulnerable.” He strode over to my micro-library, several racks of carefully arranged spools, and fingered them irreverently. “What is this?” “My library.” “So! Our memories are built into us. We have no need to refresh them.” “So is mine,” I said. “But I would learn more than I know.” I was stalling for time, waiting until he made the right opening. “Nonsense,” he said. “I know why you stay out here in the Dumps, masterless. I have heard of the forbidden drug that is sold in the mining camps such as Argon City. Is this the mechanism?” He pointed at the still. Now was the time. I mustered all my cunning, but I could not speak. Not yet. “Never mind,” he said. “I can see that it is. I shall report you, of course. It will give me great pleasure to see you dismantled. Not that it really matters, of course—now.” There it was again. The same frightening allusion that Langley had made today. I must succeed! I knew that MS-33, for all his brilliance, and newness, and vaunted superiority, was only a Secretarial. For the age of specialism was upon Earth, and General Purpose models were no longer made. That was why we were different here on Phobos. It was why we had survived. The old ones had given us something special which the new metal people did not have. Moreover, MS-33 had his weakness. He was larger,