Luis took the elevator to the ground floor and walked out aimlessly on the street. There was something queer about the man on the top floor. It took time to discover what it was. The man was not Starret--but he was disguised. His irises were stained another color and the voice was not his own--or rather it was, but filtered through an artificial larynx inserted painfully in his throat. And his face had been recently swabbed with a chemical irritant which caused the tissues beneath his skin to swell, making his face appear plumper. Luis took a deep breath. Unconsciously he had noticed details too slight for the average person to discern. This suggested something about his own past--that he was trained to recognize disguises. But more important was this: that the man was disguised at all. The reason was obvious--to avoid evoking memories. The man's name--what was it? It hadn't even been registered in the building--he'd asked on his way out. And Luise couldn't tell him. She was no longer a reliable source of information. He had to find out, and there was only one way that suggested itself. Luise was still in there, but not in physical danger. The police were lax about other things, but not about murder, and the man knew that. She might lose her memories of the past few weeks; regrettable if it happened, but not a catastrophe. [Illustration] But who was the man and what was his connection? He spent the rest of the day buying equipment--not much, but his money dwindled rapidly. He considered going back to the Shelter and then decided against it. By this time Luise would be back, and he would be tempted not to leave her. After dark, when the lights in the offices went out, he rented an aircar and set it down on the top of the building. * * * * * He walked across the roof, estimating the distances with practiced ease, as if he'd undergone extensive training and the apprenticeship period had been forgotten and only the skill remained. He knelt and fused two small rods to a portion of the roof, and then readjusted the torch and cut a small circular hole. He listened, and when there was no alarm, lifted out the section. There was nothing but darkness below. He fastened a rope to the aircar. He dropped the rope through the hole and slid down. Unless he had miscalculated, he was where he wanted to be, having bypassed all alarm circuits. There were others inside, he was reasonably certain of that, but with ordinary precautions he could avoid them. He flashed on a tiny light. He had guessed right; this was MEMORY LAB--the room he'd wanted to see this afternoon but hadn't been able to. In front of him was the door to the waiting room, and beyond that the hall. He swung the light in an arc, flashing it over a desk and a piece of equipment the nature of which he didn't know. Behind him was still another door.