The Ringworld Engineers

transfer to the Library.”

Louis remembered Mar Korssil. “They don’t seem repugnant.”

“But for rishathra? We who have no parents, we must pay society’s debt before we can mate and make a household. I lost my accumulated fund when I transferred. The transfer did not come soon enough.” She looked up into his eyes. “It was not joyful. But other times were as bad. When the vampire scent wears off, the memory does not. One remembers the smells. Blood on the Night Hunter’s breath. Corruption on the Night People’s.”

“You’re well out of that,” Louis said.

Some of the kzinti tried to stand up. Then they all fell asleep. Ten minutes later the hatch descended. Chmeee came down to take command.

It was late when the Hindmost reappeared. He looked rumpled and tired. “It seems your guess was correct,” he said. “Not only will scrith hold a magnetic field, but the Ringworld structure is webbed with superconductor cables.”

“That’s good,” said Louis. A great weight lifted from him. “That’s good! But how would City Builders know that? I can’t see them digging into the scrith to find out.”

“No. They made magnets for compasses. They traced a gridwork of superconductor lines running in hexagonal patterns through the Ringworld foundation, fifty thousand miles across. It helped them make their maps. Centuries passed before the City Builders knew enough physics to guess what they were tracing, but their guess led them to develop their own superconductor.”

“The bacteria you seeded—”

“It will not have touched superconductor buried in scrith. I’m aware that the Ringworld floor is vulnerable to meteorites. We must hope that none ever breached the superconductor grid.”

“It’s good odds.”

The puppeteer pondered. “Louis, are we still searching for the secret of massive transmutation?”

“No.”

“It would solve our problem very nicely,” said the Hindmost. “The device must have operated on a tremendous scale. Converting matter to energy must be far easier than converting matter to other matter. Suppose we simply fired a… call it a transmutation cannon at the underside of the Ringworld at its farthest distance from the sun. Reaction would put the structure back in place very nicely. Of course there would be problems. The shock wave would kill many natives, but many would live, too. The burned-off meteor shielding could be replaced at some later date. Why are you laughing?”

“You’re brilliant. The trouble is, we don’t have any reason to think there was ever a transmutation cannon.”

“I don’t understand.”

“Halrloprillalar was just making up stories. She told us so later. And after all, how would she know anything about the way the Ringworld was built? Her ancestors weren’t much more than monkeys when that happened.” Louis saw the heads dip, and snapped, “Do not curl up on me. We don’t have the time.”

“Aye, aye.”

“What else have you got?”

“Little. Pattern analysis is still incomplete. The fantasies involving the Great Ocean mean nothing to me. You try them.”

“Tomorrow.”

Sounds too low to interpret held him awake. Louis turned over in darkness and free fall.

There was light enough to see. Kawaresksenjajok and Harkabeeparolyn lay in each other’s arms, murmuring in each other’s ears. Louis’s translator wasn’t picking it up. It sounded like love. The sudden stab of envy made him smile at himself. He’d thought the boy was too young; he’d thought the woman had sworn off. But this wasn’t rishathra. They were the same species.

Louis turned his back and closed his eyes. His ears expected a rhythmic wave action; but it never came, and presently he was asleep.

He dreamed that he was on sabbatical.

Falling, falling between the stars. When the world became too rich, too varied, too demanding, then there came a time to leave all worlds behind. Louis had done this before. Alone in a small spacecraft, he had gone into the unexplored gaps beyond known space, to see what there was to see, and to learn if he still loved himself. Now Louis floated between sleeping plates and dreamed happy dream of falling between the stars. No dependents, no promises to keep.

Then a woman howled in panic, right in his ear. A heel kicked him hard, just below the floating ribs, and Louis doubled up with a breathy cry. Flailing arms battered him, then closed round his neck in a death-grip hug. The wailing continued.

Louis pried at the arms to free his throat. He called, “Sleepfield off!”

Gravity returned. Louis and his attacker settled onto the lower plate. Harkabeeparolyn stopped screaming. She let her arms be pried away.

The boy Kawaresksenjajok knelt beside her, confused and frightened. He spoke urgent questions in the City Builder language. The woman snarled.

The boy spoke again. Harkabeeparolyn answered him at length. The boy nodded reluctantly. Whatever he’d heard, he didn’t like it. He stepped into the corner, with a parting look that Louis couldn’t interpret at all, and vanished into the cargo hold.

Louis reached out for his translator. “Okay, what’s it all about?”

“I was falling!” she sobbed.

“It’s nothing to be afraid of,” Louis told her. “This is how some of us like to sleep.”

She looked up into his face. “Falling?”

“Yah.”

Her expression was easy to interpret. Mad. Quite mad… and a shrug. Visibly she braced herself. She said, “I have made myself know that my usefulness is over, now that your machines can read faster than I can. I can do one thing only to make our mission easier, and that is to ease the pain of your thwarted lust.”

“That’s a relief,” Louis said. He meant it as sarcasm; would she hear it that way? Louis was tanjed if he’d accept that kind of charity.

“If you bathe, and clean your mouth very thoroughly—”

“Hold it. Your sacrifice of your comfort to higher goals is praiseworthy, but it would be bad manners for me to accept.”

She was bewildered. “Luweewu? Do you not want rishathra with me?”

“Thank you, no. Sleepfield on.” Louis floated away from her. From previous experience he sensed a shouting match coming, and that couldn’t be helped. But if she tried physical force, she’d find herself falling.

She surprised him. She said, “Luweewu, it would be terrible for me to have children now.”

He looked down at her face: not enraged, but very serious. She said, “If I mate now with Kawaresksenjajok, I may bring forth a baby to die in the fire of the sun.”

“Then don’t. He’s too young anyway.”

“No, he’s not.”

“Oh. Well. Don’t you have — No, you wouldn’t be carrying contraceptives. Well, can’t you estimate your fertile period and avoid it?”

“I don’t understand. No, wait, I do understand. Luweewu, our species ruled most of the world because of our command of the nuances and variations of rishathra. Do you know how we learned so much about rishathra?”

“Just lucky, I guess?”

“Luweewu, some species are more fertile than others.”

“Oh.”

“Before history began, we learned that rishathra is the way not to have children. If we mate, four falans later there is a child. Luweewu, can the world be saved? Do you know that the world can be saved?”

Oh, to be on sabbatical. Alone in a singleship, light-years from all responsibility to anyone but Louis Wu. Oh,