Louis could only nod. The shocks had come too fast, from the wrong directions. He was aware that Chmeee stood beside him, dripping water, silently studying a potential enemy. The City Builders were mute. If Louis read their faces right, they were closer to awe or rapture than fear.

The protector said, "That traps you thoroughly. Soon enough you must go into stasis, and we need not discuss what happens after that. I am relieved. I wonder if I could make myself kill you."

Louis said, "We thought you were all dead."

"The Pak died off a quarter of a million years ago." The protector's fused lips and gums distorted some of the consonants, but it was speaking Interworld. Why Interworld? "A disease took them. You were right to a.s.sume that the protectors were all dead. But tree-of-life is alive and well beneath the Map of Mars. Sometimes it is discovered. I speculate that the immortality drug was made here when a protector needed funding for some project."

"How did you learn Interworld?"

"I grew up with it. Louis, don't you know me?"

It was like a knife in the gut. "Teela. How?"

Her face was hard as a mask. How could it show expression? She said, "A little knowledge. You know the adage? Seeker was looking for the base of the Arch. I paraded my superior education before him: I told him that the Arch had no base, that the world was a ring. He became badly upset. I told him that if he was looking for the place from which the world could be ruled, he should look for the construction shack."

"Repair Center," said Louis. A glance toward the flight deck showed the Hindmost as an elongated white footstool decorated in ruby and lavender gems.

"Of course it would become the Repair Center, and the center of power too," the protector said. "Seeker remembered tales of the Great Ocean. It seemed a likely choice, protected by the natural barriers of distance, storm, and a dozen predatory ecologies. Astronomers had studied the Great Ocean from vantages far along the Arch, and Seeker remembered enough to make us maps.

"We were sixteen years crossing the Great Ocean. There should be legends made from that voyage. Did you know that the Maps are stocked? The kzinti have colonized the Map of Earth. We could not have continued if we had not captured a kzinti colony ship. There are islands in the Great Ocean that are large life forms, their backs covered in vegetation, who dive when a sailor least expects it-"

"Teela! How? How could you get to be like this?"

"A little knowledge, Louis. I never did reason out the origin of the Ringworld engineers, not until too late."

"But you were lucky!"

The protector nodded. "Bred for luck, by Pierson's puppeteers meddling with Earth's Fertility Laws to make the Birthright Lotteries. You a.s.sumed it worked. It always seemed stupid to me. Louis, do you want to believe that six generations of Birthright Lottery winners produced a lucky human being?"

He didn't answer.

"Only one?" She seemed to be laughing at him. "Consider the luck of all the descendants of all the winners of the Birthright Lotteries. In twenty thousand years they must be well on their way out of the galaxy, fleeing the explosion of the galactic core. Why not aboard the Ringworld? Three million times the habitable surface area of the Earth, and it can be moved, Louis. The Ringworld is lucky for those unborn descendants of people bred for luck. If I can save the Ringworld, then it is luck for them that we came here twenty-three years ago, and luck for them that Seeker and I found the entrance in Mons Olympus. Their luck. Never mine."

"Did it happen to him too?"

"Seeker died, of course. We both went mad with the hunger for tree-of-life root, but Seeker was a thousand years too old. It killed him."

"I should never have left you," Louis said.

"I gave you no choice. I had none myself-if you believe in luck. I have little choice now. Instincts are very strong in a protector."

"Do you believe in luck?"

She said, "No. I wish I could."

Louis flopped his arms-a gesture of helplessness-and turned away. He had always known that he would meet Teela Brown again. But not like this! He waved the sleeping field on and floated.

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 att.i.tude 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 att.i.tude 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 a.n.a.lytic 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 s.p.a.cecraft 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 s.p.a.ce, 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 s.p.a.ce. 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 s.p.a.ce 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 n.o.body 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 s.p.a.cecraft. "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 trans.m.u.tation 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 pa.s.sed. 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 b.i.t.c.h.

"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 s.p.a.ce. 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 meat in an empty liquid hydrogen tank. It had fed them for months.

Finally he heard her say, "I must eat now, but I will return soon." And then there was quiet.

The few minutes of silence ended as blunt teeth closed gently on Louis's wrist. "Louis, wake. We have no time to indulge you."

Louis turned over; he killed the sleeping field. He took a moment to savor the interesting sight of a puppeteer standing next to a kzin in the prime of health. "I thought you were out of it."

"A valuable illusion that came too near reality. I was tempted to let events take their own course," said the puppeteer. "Teela Brown spoke the truth when she said we will not die. Most of the Ringworld will break up and fly free, beyond the cometary halo. We might even be found someday."

"I'm starting to feel the same way. Ready to give up."

"The protectors must have been dead for a quarter of a million years. Who told me that?"