“Look, Derec,” said Katherine. “We both want to get off this planet, I guess. At the moment, we aren’t suffering here. Sure, if we had a ship, we’d be gone by now. But as long as that Key is our only chance to get away, we simply have to find it.”

Her tone was milder now, Derec noticed, but he just spun around, turning his back on her, and went on pacing. Ever since he had found out that she was not really Katherine Ariel Burgess, as she had told him she was, he had known he could not trust her. Or, at least, he could only believe her when she was being sarcastic or condescending. When she sounded pleasant, he had to figure out what she was up to.

Besides, he still suffered from his amnesia. It was a little too awkward to demand her identity when he couldn’t even figure out his own. In fact, even raising the subject was embarrassing. The situation left him perpetually uneasy. The best place to get away from it was in the computer.

He moved past her and threw himself back into the chair. Then he started working on the keyboard before he had any idea of what he should do. He just tried to look busy.

He had declined to construct a VoiceCommand in his terminal, since he felt it a barrier between him and the labyrinth of the central computer. The computer was comprised of the top seven planner robots, or Supervisors, in the city, joined by their communication links. The central core could only be accessed in the mysterious office inside the Compass Tower, but he had had no use for it since instructing it to discontinue the excessive building and shapechanging of the city. Using only his keyboard to access the computer allowed him to bring up more raw data and to streamline the whole system when he had the time. Now it also allowed him to tinker silently.

After a moment of concentrating, his discomfort was gone. When he spoke, his voice was casual. “Actually, this computer really is kind of stupid. Not the individual Supervisors, of course, but the way they combine their information. The shapechanging loaded so much data into them so fast that they recorded it without organizing it. The computer has become too complex to work well. It needs a lot more streamlining to become efficient.”

“I thought you were streamlining it.”

“When I get the chance,” he snapped, suddenly annoyed again. He was fairly sure he could make some real progress, given time, but he was tired of her always questioning his ability with computers. It was the one subject he actually knew something about, and he had demonstrated it many times over. Since his amnesia had left him with little knowledge of himself, the knowledge he did have was very important to him. He had even learned the kind of amnesia he had, something called “fractionated, retrograde, hypnosis-resistant psychogenic amnesia”-whatever that meant.

Katherine didn’t say anything, though he remained aware that she was watching him.

“Well, we are stuck with a rather odd computer, after all,” he said. Her composure made him self-conscious about his own discomfort. He made an effort to cool off a little. “Here we are in Robot City, a place built and run and populated exclusively by robots, and we have no idea of who created it, or why. I mean, who ever heard of a planet like this?”

“I know,” she said gently. “Derec, we are in this together.”

“Let me explain the computer again. We’re sure the robots have the Key, because there is no one else here on the planet except us. No-”

“Derec, I know this part,” she said with exaggerated weariness.

“Let me go on. I’m trying to build up to my point. Look, I’ve never encountered a computer quite like this, and I’m still trying to think through how to handle it.”

“Go on.”

“The computer obviously is subject to the Three Laws of Robotics, and that should make it honor my requests for information, under the Second Law. It did not, probably for two reasons. One is prior programming, where the Second Law required the robots collectively to keep certain secrets under orders they received from another human, presumably the creator of Robot City, whoever it was.”

The Second Law of Robotics is: “ A robot must obey the orders given it by human beings except where such orders would conflict with the First Law.”

Katherine nodded quietly, now gazing at the floor. “What’s the second reason?”

“The second reason is that the computer system has apparently expanded to the point where it needs fundamental reorganization to operate efficiently. Too many parts of the system just don’t seem to know what the other parts know. All sorts of information is lost in there. Even when it does know the answer to a question, sometimes the information takes much too long to locate. And I have to think up special ways of giving orders and asking questions to get it out.

Katherine lifted her head and smiled. “We’re both getting better at that, Derec. We’ve had some practice now, especially with individual robots.”

Derec grinned. “I guess I can’t argue with that. So far, the best way to make the robots cooperate is to convince them that we’re in danger, thus activating their First Law programming.”

“I know, I know-have you forgotten my charade on Rockliffe Station with that little alien friend of yours, Wolruf? The trouble is, it’s even harder to convince them when we’re just debating. I seem to recall that we’ve both gone a few rounds with various robots that way.”

“That’s true, too.” The positronic brains of the humanoid robots were quite sophisticated, and debating with their cold logic could be frustrating. “The Supervisors were so cooperative-within their limits of programming, of course-that it’s too bad we can’t just try to work with them to get the Key back.”

“They haven’t even admitted that they took it from our hiding place on the Compass Tower,” said Katherine. “Why would they cooperate with us?”

“I’m sure they wouldn’t, or couldn’t. That’s why we’ll have to try locating the Key without confronting them. The longer it takes them to realize that we’re after it, the more freedom we’ll have.”

Despite their current rapport, Derec was afraid that if he didn’t stay on the computer, Katherine would make more comments about his incompetence. She might even call him a quitter. Determined not to give her any excuse for that, he continued to play idly on the keyboard.

Katherine pulled up the other chair-they only had two-and sat down. “Derec, let’s try to think up some questions I could ask some of the other robots, not the Supervisors. I know they won’t answer our direct questions about the Key, but I’ve gotten information out of them before. Like you were saying, we just have to think up the right questions. Stuff they have to answer because of the Laws.”

He nodded. “Or else questions they don’t realize will lead us anywhere. The problem is, that’s what I’ve been trying to do through the computer. I guess I just don’t know.”

All they really knew about the Key to Perihelion was that it was a teleportation device and that it had been taken from the place where they had hidden it. Obviously, the robots had taken it, and so far they had not even revealed that much information. Since the Key seemed to belong here, or at least had some special relationship to Robot City, the robots apparently did not feel that they had stolen it. They were incapable of dishonesty as such.

“We know the robots were searching for the Key for a long time,” said Derec. “So whatever they’ve done with it must have been part of their long-term programming.”

He could certainly use her help, but he didn’t know if he trusted her enough to speak freely. At one point, he had offered to let her use it to leave the planet while he stayed, and she had chosen to remain here with him. That had been some time ago, though. Sometimes they seemed very close, but he still wasn’t sure that if she got to the Key first, she would share its use with him. She had some kind of chronic physical condition-precisely what kind of condition was her secret-and she just might be in a bigger hurry to get off the planet than she claimed.