The Ringworld Engineers

The librarian shook her head. “I don’t understand.”

“With the attitude jets in action we extend the life span of the Ringworld by as much as a year. An extra year for three times ten to the thirteenth intelligent beings is equivalent to giving everyone on Earth an extra thousand years of life span. A worthy accomplishment. My collaborators agreed, even those who are not protectors.”

Louis could trace the lines of Teela Brown’s face in the protector’s leather mask. Bulges at the hinges of the jaw, a skull swollen to accommodate more brain tissue… but it was Teela, and it hurt terribly. Why doesn’t she go away?

Habits die hard, and Louis had an analytic mind. He thought, Why doesn’t she go away? A dying protector in a doomed artificial world! She doesn’t have a minute to spare talking to a collection of trapped breeders. What does she think she’s doing?

He turned to face her. “You formed the repair crew, did you? Who are they?”

“My appearance helped. Most hominids will at least listen to me. I gathered a team of several hundred thousand from various species. I brought three here to become protectors: from the Spill Mountain People and the Night People and the Vampires. I hoped that they would see a solution hidden to me. Their viewpoints would differ. The vampire, for instance, was non-sentient before the change.

“They failed me,” said Teela. She certainly behaved as if she had time. Time to entertain trapped aliens and breeders until the Ringworld brushed the shadow squares! “They saw no better solution. And so we mounted the remaining Bussard ramjets on the rim wall. We have now mounted all but the last. Under the direction of the remaining protector, my team will gear the remaining Ringworld spacecraft to carry them to safety around some nearby star. Some Ringworlders will survive.”

“We’re back to the original question,” Louis said. “Your crew is hard at work. What are you doing here?” I’m right! She’s trying to tell us something!

“I came to prevent the murder of fifteen hundred thousand million intelligent hominids. I recognized the neutrino exhaust from thrusters built in human space, and I came to the only feasible scene of the crime. I waited. Here you are.”

“Here we are,” Louis agreed. “But you know tanj well that we didn’t come to commit any murders whatever.”

“You would have.”

“Why?”

“I can’t tell you that.”

Yet she showed no inclination to end the conversation. It was a strange game Teela was playing. They would have to guess at the rules. Louis asked, “Suppose you could save the Ringworld by killing one and a half trillion inhabitants out of thirty trillion. A protector would do that, wouldn’t she? Five percent to save 95 percent. It seems so… efficient.”

“Can you empathize with that many thinking beings, Louis? Or can you only imagine one death a time, with yourself in the starring role?”

He didn’t answer.

“Thirty billion people inhabit human space. Picture all of them dead. Picture fifty times that population dying of, let us say, radiation poisoning. Do you sense their pain, their regrets, their thoughts for each other? From that many? The numbers are too large. Your brain won’t handle it. But mine will.”

“Oh.”

“I can’t make it happen. I can’t let it happen. I knew I must stop you.”

“Teela. Picture a shadow square sweeping down the width of the Ringworld at around seven hundred miles per second. Picture a thousand times the population of human space dying as the Ringworld disintegrates.”

“I do.”

Louis nodded. Pieces of a puzzle. Teela would give them as many pieces as she could. She couldn’t make herself hand them a finished picture. So keep fishing for pieces. “Did you say the remaining protector? There were four, and now there’s one plus you? What happened to the others?”

“Two protectors left the repair crew at the same time I did. They must have left separately. Perhaps they found the clues that announced your arrival. I felt it necessary to track them down and stop them.”

“Really? If they were protectors, they could no more kill a trillion and a half thinking hominids than you could.”

“They might arrange for it to happen, somehow.”

“Somehow.” Careful with the wording, now. He was glad that nobody was trying to interrupt. Not even Chmeee, the soft-spoken diplomat. “Somehow, let breeders reach the only place on the Ringworld where the crime can be committed. Would that have been their strategy, if you hadn’t stopped them?”

“Perhaps.”

“Let these carefully chosen breeders be protected from smelling tree-of-life, somehow.” Pressure suits! That was why Teela had been looking for an interstellar spacecraft. “Let them become aware of the situation, somehow. And somehow a protector has to double-think his way out of killing them before they see the solution and use it, killing astronomical numbers of breeders to save even more. Is that what you think you prevented?”

“Yes.”

“And this is the right place?”

“Why else would I be waiting here?”

“There’s one protector left. Will he come after you?”

“No. The Night People protector knows that she alone is left to supervise the evacuation. If she tries to kill me and I kill her, breeders alone might die en route.”

“You do seem to kill very easily,” Louis said bitterly.

“No. I can’t kill 5 percent of the Ringworld populace, and I don’t know that I can kill you, Louis. You are a breeder of my species. On the Ringworld you are alone in that regard.”

“I thought of ways to save the Ringworld,” said Louis Wu. “If you know of a large-scale transmutation device, we know how to use it.”

“Certainly the Pak had none. That was not your cleverest deduction, Louis.”

“If we could punch a hole under one of the Great Oceans, then control the outflow, we could use the reaction to put the Ringworld back in place.”

“Clever. But you can’t make the hole and you can’t plug it. Furthermore, there is a solution that does less damage, yet it is too much damage, and I cannot permit it.”

“How would you save the Ringworld?”

The protector said, “I can’t.”

“Where are we? What went on in this part of the Repair Center?”

A long moment passed. The protector said, “I may not tell you more than you know. I don’t see how you can escape, but I must consider the possibility.”

“I quit,” said Louis Wu. “I concede. Tanj on your silly game.”

“All right, Louis. At least you will never die.”

Louis closed his eyes and curled up in free fall. Pious bitch.

“I will keep you company until you must go into stasis,” Teela said. “I can do little else for your comfort. You, what are your names and where are you from? You are of the species that conquered the Ringworld and the stars.”

Chattering. Why weren’t people born with flaps over their ears? Was there a hominid with that trait?

Kawaresksenjajok asked. “What is a magician’s position regarding rishathra?”

“That is important when you meet a new species, isn’t it, child? My position is that rishathra is for breeders. But we do love.”

The boy was enjoying himself immensely. His sense of wonder was stretched nowhere near its limits. Teela told of her great journey. Her band of explorers had been trapped by Grogs on the Map of Down, then freed by the odd inhabitants. On Kzin there were hominid animals imported long ago from the Map of Earth, bred for special traits until they differed as thoroughly as dogs do in human space. Teela’s crew had hidden among them. They had stolen a kzinti colony ship. They had killed one of the krill-eating island-beasts for food, freezing the