For that matter, he was worried about her. He wanted to get her some human medical care, and that meant getting away from Robot City. However, he did not want to be left behind.

“What they’re doing is obvious,” said Katherine. “They plan to teleport somewhere. That’s all the Key is good for, as far as we know.”

“But where do they have to go? The planet is all theirs already, except for us.”

“Oh, Derec.” She sounded exasperated. “At some point, they’re going to teleport off the planet entirely, just like we want to do.”

“But why-” Derec stopped. They couldn’t possibly know why, because they didn’t know the robots’ purpose here on the planet in the first place. Discussing the robots’ motives would not get them very far. “Well, let’s think out loud for a minute. On the asteroid where they found the Key, they were programmed to self-destruct when they were under attack. The Key and the element of secrecy were much more important than the robots or other materials to the person who programmed them. Cost was absolutely not a real concern. And that programming was critically important, since it violated the Third Law.”

The Third Law of Robotics is: “ A robot must protect his own existence as long as such protection does not conflict with the First or Second Laws. “

“So their self-destruction-probably for the purpose of secrecy-must have been programmed by their creator under the First or Second Laws.” She thought a moment. “There’s that minimalist engineering again, which you keep talking about. “

“Now, wait a minute.” He turned in his chair to face her. “Haven’t I already explained this? When I use that term, I mean these designs that we keep seeing that make things easy to use, even though the technology may have to be much more complicated than necessary to make it that easy.” He laughed, glad to have the advantage on her for a change. “What’s that got to do with robots melting themselves down into hot puddles of molten junk?”

“Well, it’s the same attitude. It’s not the engineering as such, but the priorities. The creator of Robot City doesn’t care about conserving materials.”

“Oh.Well…you might have a point, I suppose. Of course, they have all the materials they want, since there is no competition here. I…say!” He suddenly turned back to the console. Without mentioning the Key at all, he called up the records of supply requisitions. Then he searched out unusual movements of materials with a top-level priority. Several locations were given. “Ha! What do you bet they’ve just set up some kind of place to keep the Key?”

“Yes!” Katherine threw her arms around his neck and gave him a quick squeeze. “They must have. Considering how important it is, they’ll want it under the tightest security you ever saw on this planet.” She laughed. “And if we get too close, maybe these suicidal robots will start melting themselves down into hot little puddles of molten junk again.”

Derec had stiffened in surprise at her embrace and felt his face grow hot with embarrassment again. They had been affectionate at times before, but arguments always seemed to follow. He had no idea how she really felt.

Katherine went on excitedly. “Do you suppose a particular robot is in charge? That would tell us who to look for.”

Glad to have something else to do, Derec called up a list of duty changes among the robots. That list included geographical changes of assignment where they were pertinent. Major changes in reorganization were still taking place in the wake of the building frenzy that Derec had recently stopped. Now he correlated that information with the list of locations for which an abundance of materiel had just been requisitioned. All at once, he had the number of a single robot. “There it is!”

Katherine was looking over his shoulder. “And, look-it has a huge crew that’s just been assigned to work under it. Wow, this serial number is a mouthful.” Normally, robots with a lot of human contact were given language names instead of numbers or duty designations, but on Robot City the robots had no reason to assume that human contact would be made with any frequency; only the Supervisors had been given names.

“Watch this. Let’s see. Key…How about Keymo?” He hit a sequence of keys.

“What did you do?”

“I’ve given it a name. It’ll be easier for us to remember. Now that it’s in the computer, it’ll respond to that as well as its number. The other robots can learn it if they ask.”

“I didn’t know you could do that.”

He grinned up at her. “I just figured it out today.”

“Congratulations. Say, Derec…”

“Yeah?”

“Lookat the size of that crew it has assembled. What could they possibly be doing?”

Derec shrugged. “Security? You’re right about that part. The robots will have that Key guarded heavily.”

“What would they be afraid of on Robot City?” Besides, they can have other kinds of security systems. They don’t need a bunch of robots just standing around.”

“You got me, kiddo.”

“What about their last duties? What kind of skills have they specialized in?”

He started calling up a list of their previous duties, and spoke as he worked. “I know that skills matter to some of the robots, but I’m not sure how much. Certainly, for information, they can all draw upon the central computer. If they can manage to get the data out of that tangled contraption, anyone of them can know practically anything that any robot here knows.” He looked at the list that came up. “There we are. Hmm-let me try this.” In a couple of strokes, he had the computer subdivide the list according to previous duties that the various robots had in common.

“I don’t see much of a pattern,” Katherine admitted after a moment.

Derec shook his head. “I don’t, either. They have all kinds of different backgrounds.”

“Maybe they have something else in common. Can you ask the computer to tell you if they have some other common trait?”

“I can ask it anything we can think of.” Derec smiled ruefully. “Whether or not I get a civilized answer is another matter.” A moment later, he had a new list in front of them. He looked it over and let out a slow breath. “Wow.”

“It must be the Key,” Katherine said softly.

According to the computer, the robots on this new duty roster had been selected for their absolute peak efficiency. They had recorded the fewest breakdowns, the shortest repair times, and the finest work records. Those who had experienced contact with humans had consistently reached any necessary decisions regarding the Laws with the least time and effort, though of course all the robots reached the correct decisions eventually. This team represented the best robots from all over Robot City.

“This Keymo must be the best of the best,” said Derec, “considering that they put him in charge. Tangling with this bunch is going to be tough.”

“Think of it this way: if we can talk him out of the Key to Perihelion, we can talk these robots into anything.”

Derec looked up at her, smiling weakly. When he caught her eye, they both laughed.

“All right,” Katherine conceded. “If we can talk them out of the Key to Perihelion, we won’t need anything else from them.”

“We should go to Keymo prepared with an argument.” Derec got up and walked over to the kitchen area. “ And since we can’t count on finding food outside our apartment here, we’d better eat first. “ He looked over the limited list of fare that the chemical processor could simulate. “I’m afraid we’re out of the fresh produce. We’ll have to request another delivery. Right now, we can’t afford the time.”

Katherine joined him, peering over his shoulder with a look of distaste. “That’s another good reason for us to get off this planet. This stuff tastes terrible. “

“The robots did what they could, I guess. Before we got here, they just had no reason to concern themselves with cooking. Maybe we’re lucky they could make a chemical processor that’s even this tolerable.”