Larry Niven: The Ringworld Engineers

The Hindmost had the right idea. Crawl into your own navel.

But humans can’t bury their ears. Louis floated half curled up, with his arms over his face. But he heard:

“Speaker-To-Animals, I congratulate you on regaining your youth.”

“My name is Chmeee.”

“I beg your pardon,” the protector said. “Chmeee, how did you come here?”

The kzin said, “I am thrice trapped. Kidnapped by the Hindmost, barred by Louis from escaping the Ringworld, trapped underground by Teela Brown. This is a habit I must break. Will you fight me, Teela?”

“Not unless you can reach me, Chmeee.”

The kzin turned away.

“What do you want from us?” That was Kawaresksenjajok, speaking diffidently in the City Builder tongue, echoed in Interworld by the translator.

“Nothing.” Teela, in City Builder.

“Then what are we doing here?”

“Nothing. I’ve seen to it that you can do nothing.”

“I don’t understand.” The boy was near tears. “Why do you want to bury us underground?”

“Child, I do what I must. I must prevent one point five times ten to the twelfth murders.”

Louis opened his eyes.

Harkabeeparolyn objected heatedly. “But we’re here to prevent deaths! Don’t you know that the world is off center, sliding into the sun?”

“I know of that. I formed the team that has been remounting the Ringworld’s attitude jets, reversing the damage done by your species.”

“Luweewu says that it isn’t enough.”

“It isn’t.”

They had Louis Wu’s complete attention now.

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.”