The Ringworld Engineers

Refusing sex took tact in Louis’s culture. He had told her that he was afraid of jarring her arm, which he was. It was equally true that he couldn’t seem to work up an interest. He wondered if tree-of-life had affected him so. But he sensed no lust in himself for yellow roots, nor even for a wire trickling electric current.

This morning he seemed to have no strong urges at all.

Fifteen hundred billion people …

The Hindmost said, “Let us accept Louis’s judgment regarding Teela Brown. Teela brought us here. Her intent matched our own. She gave us as many clues as she could. But what clues? She was fighting both sides of a battle. Was it important for her to create three more protectors, then kill two of them? Louis?”

Louis, lost in thought, felt four sharp points prick his skin above the carotid artery. He said, “Sorry?”

The Hindmost started to repeat himself. Louis shook his head violently. “She killed them with the meteor defense. She fired the meteor defense, twice, at targets other than our vitally necessary selves. We were allowed to watch it without being in stasis at the time. Just another message.”

Chmeee asked, “Do you assume that she could have chosen other weapons?”

“Weapons, times, circumstances, number of operating protectors—she had considerable choice.”

“Are you playing games with us now, Louis? If you know something, why not tell us?”

Louis’s guilty glance at the City Builders showed Harkabeeparolyn trying to stay awake, Kawaresksenjajok listening intently. A pair of self-elected heroes waiting their chance to help save the world. Tanj. He said, “One point five trillion people.”

“To save twenty-eight point five trillion, and ourselves.”

“You didn’t get to know them, Chmeee. Not as many, anyway. I was hoping one of you would think of this. I’ve been thrashing around in my head trying to see some—”

“Know them? Know who?”

“Valavirgillin. Ginjerofer. The king giant. Mar Korssil. Laliskareerlyar and Fortaralisplyar. Herders, Grass Giants, Amphibians, Hanging People, Night People, Night Hunters … We’re supposed to kill 5 percent to save 95 percent. Don’t those numbers sound familiar to you?”

It was the puppeteer who answered. “The Ringworld’s attitude jet system is 5 percent functional. Teela’s repair crew remounted them over 5 percent of the arc of the Ringworld. Are these the people who must die, Louis? The people on that arc?”

Harkabeeparolyn and Kawaresksenjajok stared in disbelief. Louis spread his arms, helpless. “I’m sorry.”

The boy cried, “Luweewu! Why?”

“I promised,” said Louis. “If I hadn’t promised maybe I’d have a decision to make. I told Valavirgillin I’d save the Ringworld no matter what it took. I promised I’d save her, too, if I could, but I can’t. We don’t have time to find her. The longer we wait, the bigger the force pushing the Ringworld off center. So she’s on the arc. So’s the floating city, and the Machine People empire, and the little red carnivores and the Grass Giants. So they die.”

Harkabeeparolyn beat the heels of her hands together. “But this is everyone we know in the world, even by reputation!”

“Me too.”

“But this leaves nothing worth saving! Why must they die? How?”

“Dead is dead,” said Louis. Then, “Radiation poisoning. Fifteen hundred billion people of twenty or thirty species. But only if we do everything exactly right. First we have to find out where we are.”

The Puppeteer asked reasonably, “Where do we need to be?”

“Two places. Places that control the meteor defense. We have to be able to guide the plasma jets, the solar flares. And we have to disco

“I have already found these places,” the Hindmost said. “While you were gone, the meteor defense fired, possibly to destroy the lander. Magnetic effects scrambled half my sensor equipment. Nonetheless I traced the origin of the impulse. The massive currents in the Ringworld floor that make and manipulate solar flares derive from a point beneath the north pole of the Map of Mars.”

Chmeee said, “Perhaps the equipment must be cooled—”

“Futz that! What about the laser effect?”

“Activity there came hours later: smaller electrical effects, patterned. I told you of this source. It is just over our heads, by ship’s orientation.”

“I take it we must disco

Louis snorted. “It’s easy. I could do it with a flashlight-laser or a bomb or the disintegrator. Learning how to make solar flares will be the hard part. The controls probably weren’t designed for idiots, and we don’t have too much time.”

“And afterward?”

“Then we put a blowtorch against inhabited land.”

“Louis! Details!”

He would be speaking a death sentence for a score of species.

Kawaresksenjajok wouldn’t show his face. Harkabeeparolyn’s face was set like stone. She said, “Do what you must.”

He did. “The attitude jet system is only 5 percent operational.”

Chmeee waited.

“Operating fuel is hot protons streaming from the sun. The solar wind.”

The puppeteer said, “Ah. We flare the sun to multiply the fuel intake by a factor of twenty. Life forms beneath the flare die or mutate drastically. Thrust increases by the same factor. The attitude jets either take us to safety or explode.”

“We don’t really have time to redesign them, Hindmost.”

Chmeee said, “Irrelevant unless Louis is totally wrong. Teela inspected those motors while mounting them.”

“Yah. If they weren’t strong enough, she talked herself into adding an overdesign safety factor. Guarding against the mischance of a large solar flare. She knew that was possible. Doublethink!”

“To guide the flare is not necessary to us, merely convenient,” the kzin continued. “Let the laser-generating subsystem be disco

Louis nodded. “We’d like something a little more accurate. We’d do the job faster and kill less people. But … yah. We can do it all. We can do it.”

The Hindmost came with them to inspect the components of the meteor defense. Nobody talked him into that. The sensor devices they dismounted from Needle had to be operated by a puppeteer’s lips and tongue. When he suggested teaching Louis how to manipulate the controls using a pick and tweezers, Louis laughed at him.

The Hindmost spent some hours in the blocked section of Needle. Then he followed them out through the tu

It wasn’t necessary to use a bomb on the laser subsystem. Finding the off switch took the Hindmost a full day and a disc-load of the dismounted instruments, but it was there.

The web of superconductor cables had its nexus in the scrith twenty miles beneath the north pole of the Map of Mars. They found a central pillar twenty miles tall, a sheath of scrith enclosing the cooling pumps for the Map of Mars. The complex at the bottom must be the control center, they decided. They found a maze of huge airlocks, and each had to be passed by solving some kind of design puzzle. The Hindmost handled that.

They passed through the last door. Beyond was a brightly lighted dome, and dry-looking soil with a podium in the center, and a smell that sent Louis spi

Presently Chmeee joined them. “The path led across a patch of soil beneath artificial sunlights. The automated gardening equipment has failed, and few plants still grow, but I recognized them.”