The Ringworld Engineers

Chapter 13 — Origins

The lander cruised five miles up at just under sonic speed.

Thirteen thousand miles was no great distance for the lander. Louis’s caution irked the kzin. “Two hours and we can be dropping onto the floating city, or rising from underneath! One hour, without serious discomfort!”

“Sure. We’d have to go out of the atmosphere with the fusion drive blazing like a star, but sure. Remember how we reached Halrloprillalar’s floating jail? Upside down in midair, with the motors burned out of our flycycles?”

Chmeee’s tail thumped the back of his chair. He remembered.

“We don’t want to be noticed by any old machinery. The superconductor plague doesn’t seem to have got it all.”

Grassland gave way to patterns of cultivation, then to a watery jungle. Vertical sunlight reflected back at them from between the trunks of flowering trees.

Louis was feeling wonderful. He wouldn’t let himself see the futility of his war on the sunflower patch. It had worked. He had set himself a task; he had accomplished it with intelligence and the tools at hand.

The swamp seemed to go on forever. Once Chmeee pointed out a small city. It was difficult to see, with water half drowning the buildings, and vines and trees trying to pull them down. The architectural style was strange. Every wall and roof and door bulged outward a little, leaving the streets narrow in the center. Not built by Halrloprillalar’s people.

By midday the lander had traveled further than Ginjerofer or the king giant would travel in their lifetimes. Louis had been foolish to question savages. They were as far from the floating city as any two points on Earth.

The Hindmost called.

Today his mane was a swirling rainbow, dyed in streamers of primary colors. Behind him puppeteers flickered along lines of stepping discs, clustered at shop windows, brushed against each other without apology or resentment, all in a murmur of music with flutes and clarinets predominating: puppeteer language. The Hindmost asked, “What have you learned?”

“Little,” said Chmeee. “We have wasted time. There was certainly a great solar flare seventeen falans ago — about three and a half years — but we guessed that much. The shadow squares closed to protect the surface. Their guidance system must operate independently of the Ringworld’s.”

“We could guess that too. No more?”

“Louis’s hypothetical Repair Center is certainly inactive. This swamp below us was not designed. I imagine a major river silted up to block the outflow of a sea. We find a variety of hominids, some intelligent, some not. Of those who built the Ringworld we find no trace, unless they were Halrloprillalar’s ancestors. I am inclined to think they were.”

Louis opened his mouth… and glanced down at a threshold pain in his leg. He found four kzinti claws just resting on his thigh. He shut his mouth. Chmeee continued, “We have not met any of Halrloprillalar’s species. Perhaps they were never a dense population. We hear rumors of another race, the Machine People, who may rise to replace them. We go to seek them.”

“The Repair Center is inactive, yes,” the Hindmost said briskly. “I have learned much. I have put a probe to work—”

“You have two probes,” Chmeee said. “Use both.”

“I hold one in reserve, to refuel Needle. With the other I have learned the secret of the spill mountains. See—”

The far right screen showed a probe’s-eye view. It raced along the rim wall; passed something, too quick for detail; slowed, turned, moved back.

“Louis advised me to explore the rim wall. The probe had barely started its deceleration routine when it found this. I thought it worth investigating!”

There was a swelling on the rim wall — a tube hooked over the lip. It was molded, flattened against the rim wall, and was made of the same translucent gray scrith. The probe eased toward it until the camera was looking up into a pipe a quarter-mile across.

“Much of the Ringworld’s design shows a brute-force approach,” the Hindmost was saying. And the probe moved alongside the pipe, over the lip, and down the outer face of the rim wall to where the pipe disappeared into the foamed material that formed a meteor shield for the Ringworld’s underside.

“I see,” Louis said. “And it wasn’t working?”

“No. I tried to trace the pipe and had some success.”

The scene jumped. Now it showed dark racing motion as the probe cruised a good distance outward from the Ringworld. Inverted landscape passed above, seen by infrared light. The probe slowed, stopped, moved upward.

If a meteor struck the Ringworld, it had to fall first from interstellar space; and it struck with that velocity plus the Ringworld’s own seven hundred and seventy miles per second. A meteor had struck here. The plasma cloud had drawn a savage gouge across hundreds of miles of sea bottom, vaporizing the protective foam. There in the gouge was a length of pipe a few hundred feet in diameter. It led up into the sea bottom.

“A recycling system,” Louis murmured.

The puppeteer said, “Without some counterbalance to erosion, the Ringworld’s topsoil would all be in the sea bottoms in a few thousand years. I expect the pipes ran from the sea bottoms along the underside and up over the rim wall. They deposit sea-bottom sludge on the spill mountains. Much of the water would boil away in the near vacuum at the peak, thirty miles high. The mountain gradually collapses under its own weight. Material moves from the rim walls inward, carried by winds and rivers.”

Chmeee said, “Mere supposition, but plausible. Hindmost, where is your probe now?”

“I intend to bring it out from under the Ringworld and reinsert it into the rim transport system.”

“Do that. Does the probe have deep-radar?”

“Yes, but the range is short.”

“Deep-radar the spill mountains. The spill mountains are… perhaps twenty to thirty thousand miles apart? Thus we may find on the order of fifty thousand spill mountains along both rim walls. A handful of those would make a fine hiding place for the Repair Center.”

“But why should the Repair Center be hidden?”

Chmeee made a rude noise. “What if the subject races should revolt? What of an invasion? Of course the Repair Center is hidden, and fortified too. Search every spill mountain.”

“Very well. I will scan the starboard rim wall in one Ringworld rotation.”

“Scan the other rim afterward.”

Louis said, “Keep the cameras going too. We’re still looking for attitude jets… though I’m starting to think they had something else going.”

The Hindmost clicked off. Louis turned to the window. It had been tickling at his attention all along: a pale thread that curved along the edge of the swamp, straighter than a river. Now he pointed out the barely visible pair of dots moving along its length. “I think we need a closer look at that. Why don’t you take us down?”

It was a road. From a hundred feet up it was rough-surfaced, stony stuff: white stone poured in a stream. Louis said, “The Machine People, I presume. Shall we track those vehicles?”

“Let us wait until we are closer to the floating city.”

Giving up a present opportunity seemed silly, but Louis was afraid to object. The kzin’s tension was thick enough to smell.

The road avoided the low, wet areas. It seemed in good repair. Chmeee followed it at low speed, a hundred feet up.

Once they passed a handful of buildings, the biggest of which seemed to be a chemical plant. Several times they watched boxy vehicles pass below them. They were seen only once. A box stopped suddenly, and humanoid shapes spilled out, ran in circles, then produced sticks which they pointed at the lander. A moment later they were out of sight.

There were great pale shapes in the wet jungle. They couldn’t be glacier-scoured boulders; not here. Louis wondered if they might be tremendous fungi. He stopped wondering when he saw one move. He tried to point it out to Chmeee. The kzin ignored him.

The road curved away to antispinward as it approached a range of craggy mountains; it jogged through a notch in the range, rather than carving its own path, then jogged right to run alongside the swamp again.

But Chmeee swerved left and accelerated. The lander streaked along the portward side of the range, trailing a plume of fire. Abruptly the kzin spun the lander around, braked, and set down at the foot of a granite cliff.

He said, “Let us step outside.”

The scrith shell of the mountain would block the Hindmost’s microphones, but they’d feel still safer outside the lander. Louis followed the kzin.

The day was bright and sunny — too bright, as this arc of the Ringworld approached its nearest point to the sun. A stiff warm wind was blowing. The kzin asked, “Louis, were you about to tell the Hindmost of the Ringworld engineers?”

“Probably. Why not?”

“I assume we’ve come to the same conclusion.”

“Doubtful. What would a kzin know of Pak protectors?”

“I know everything in the records of the Smithsonian Institute, what little there is. I have studied the testimony of the asteroid belt miner, Jack Brennan, and holos of the mummified remains of the alien Phssthpok and of the cargo pod from his ship.”

“Chmeee, how did you get hold of that stuff?”

“Does it matter? I was a diplomat. The existence of the Pak has been a Patriarch’s Secret for generations, but any kzin who must deal with humans is required to study the records. We learn to know our enemy. I may know more of your ancestry than you do. And I surmise that the Ringworld was built by Pak.”

Six hundred years before Louis Wu’s birth, a Pak protector arrived in Sol system on a mission of mercy. It was through this Phssthpok, via the Belter Jack Brennan, that historians learned the rest of the story.

The Pak were native to a world in the galactic core. They lived their lives in three stages: child, breeder, protector. The adults or breeders were just intelligent enough to swing a club or throw a stone.

In middle age, if they lived long enough, Pak breeders developed a compulsion to gorge on the plant called tree-of-life. A symbiotic virus in the plant triggered the change. The breeder lost its gonads and teeth. Its skull and brain expanded. Lips and gums fused into a hard, blunt beak. Its skin wrinkled and thickened and hardened. Its joints became enlarged, offering a larger moment arm to the muscles, increasing their strength. A two-chambered heart developed in the groin.

Phssthpok came tracking a Pak colony ship that had reached Earth more than two million years earlier.

The Pak were in a constant state of war. Previous colonies to nearby worlds in the galactic core had always been overrun by subsequent waves of ships. Perhaps that was the reason this ship had come so far.

The colony was large and well-equipped, and guided by beings tougher and smarter than humans. It had failed nonetheless. Tree-of-life grew in Earth’s soil, but the virus didn’t. The protectors had died out, leaving a lost population of Pak breeders to fend for themselves… and leaving records of a cry for help that had crossed thirty thousand light-years to the Pak home world.

Phssthpok found those records in an ancient Pak library. And Phssthpok crossed thirty thousand light-years, all alone in a slower-than-light craft, seeking Sol system. The resources that built that craft, in knowledge and minds and materials, were resources Phssthpok had conquered and held by war. His cargo pod was jammed with tree-of-life roots and seeds, and bags of thallium oxide. His own research had discovered the need for that unusual soil additive.

It might have occurred to him that the breeders would mutate.

Among the Pak a mutant stood no chance. If the children smelled wrong to their protector forefathers, they were killed. On Earth — perhaps Phssthpok counted on a lower mutation rate, this far from the savage cosmic-ray density among the core suns. Perhaps he took his chances.

The breeders had mutated. By Phssthpok’s time they showed little resemblance to the Pak breeder — barring certain changes at middle age, when the production of eggs stopped in females, and when both sexes showed wrinkling of skin, lost teeth, swelling of joints, and a restlessness and dissatisfaction that was all that remained of the hunger for tree-of-life. Later in life, heart attacks would result from the lack of the second heart.

Phssthpok learned none of this. The rescuer died almost painlessly, with no more than a suspicion that those he intended to rescue had become monsters, and had no need of him at all.

Such was the tale that Jack Brennan told to United Nations representatives before his disappearance. But Phssthpok was dead by then, and Jack Brennan’s testimony was doubtful. He had eaten tree-of-life. He had become a monster; his braincase in particular was expanded and distorted. Perhaps he had become mad too.

It was as if a load of spinach noodles had been spilled all over this rocky area. Strips of greenery, fuzzy to the touch, hugged the ground in places where dirt had packed itself between the boulders. Clouds of insects buzzed around their ankles, staying within inches of the ground.

“Pak protectors,” said Louis. “That’s what I thought, but I’ve been having trouble making myself believe it.”

Chmeee said, “The vacuum suits and the Grass Giant’s armor show their shape: humanoid, but with enlarged joints and a face pushed forward. There is more proof. We’ve met so many hominids, all different. They had to be derived from a common ancestor: your own ancestor, the Pak breeder.”

“Sure. It’d also tell us how Prill died.”

“Does it?”

“Boosterspice was tailored for the metabolism of Homo sapiens. Halrloprillalar couldn’t use it. She had her own longevity drug, and it could be used by a number of species. It struck me that Prill’s people might have made it from tree-of-life.”

“Why?”

“Well, the protectors lived thousands of years. Some factor of tree-of-life, or a subcritical dose of it, might trigger just enough of the change to do that for a hominid. And the Hindmost says Prill’s supply was stolen.”

Chmeee was nodding. “I remember. One of your asteroid mining craft boarded the abandoned Pak spacecraft. The oldest man in the crew smelled tree-of-life and went mad. He ate beyond the capacity of his belly, and died. His crewmates could not restrain him.”

“Yah. Now, is it too much to expect that the same thing happened to some UN lab assistant? Prill walks into the UN building carrying a flask of Ringworld longevity drug. The UN wants a sample. A kid barely too young for his first dose of boosterspice — forty, forty-five — opens the flask. He’s got the eyedropper all ready. Then he gets a whiff. He drinks it all.”

Chmeee’s tail lashed air. “I would not go so far as to say that I liked Halrloprillalar. Still, she was an ally.”

“I liked her.”

The hot wind blew around them, filled with dust. Louis felt harried. They wouldn’t get another chance to talk in privacy. The probe that relayed signals to and from Needle would soon be too high up the Arch for this kind of trick to work.

“Can you think like a Pak for me, Chmeee?”

“I can try.”

“They put maps all over the Great Oceans. Instead of mapping Kzin and Down and Mars and Jinx, can you tell me why Pak protectors wouldn’t just exterminate the kzinti and Grogs and martians and bandersnatchi?”

“Uurrr. Why not? The Pak would not flinch at exterminating alien species, according to Brennan.”

Chmeee paced as he mulled the problem. He said, “Perhaps they expected to be followed. What if they lost a war; what if they expected the winners to come hunting them? To the Pak, a dozen burnt-out worlds within a dozen light-years of one another might indicate the presence of Pak.”

“Mmm… maybe. Now tell me why they’d build a Ringworld in the first place. How the futz did they expect to defend it?”

“I would not attempt to defend a structure so vulnerable. Perhaps we will learn. I have also wondered why Pak would come to this region of space in the first place. Coincidence?”

“No! Too far.”

“Well?”

“Oh… we can guess. Suppose a lot of Pak wanted to run as fast and as far as they could. Again, say they lost a war. Got kicked off the Pak world. Well, there was one safe route out into the galactic arms, and it was mapped. The first expedition, the one that settled Earth, got to Sol system without running into any danger they couldn’t handle. They sent back directions. So the losers followed them. Then they set up shop a good safe distance from Sol system.”

Chmeee mulled that. Presently he said, “However they came here, the Pak were intelligent and warlike xenophobes. That has implications. The weapon that vaporized half of Liar, the weapon you and Teela persisted in calling a meteor defense, was almost certainly programmed to fire on invading ships. It will fire on Hot Needle of Inquiry or the lander, given the chance. My second point is that the Hindmost must not learn who built the Ringworld.”

Louis shook his head. “They must be long gone. According to Brennan, a protector’s only motivation is to protect his descendants. They wouldn’t have let mutations develop. They’d never have let the Ringworld start sliding into the sun.”

“Louis—”

“In fact they must have been gone hundreds of thousands of years. Look at the variety of hominids we’ve found.”

“I would say millions of years. They must have departed soon after the first ship called for help, and died soon after completing the structure. How else would all of these varieties have had time to develop? But—”

“Chmeee, look: suppose they finished the Ringworld a mere half million years ago. Give the breeders a quarter of a million years to spread out, with the protectors fighting no wars because the territory’s virtually unlimited. Then let the protectors die off.”

“From what?”

“Insufficient data.”

“Accepted. Well?”

“Let the protectors die off a quarter of a million years ago. Give the breeders a tenth the time it took humans to evolve on Earth. A tenth of the time, and a lot of nice gaps in the ecology because the protectors didn’t bring anything to prey on the breeders, and a base population in the trillions.

“See? On Earth there were maybe half a million breeders when the protectors died out. On the Ringworld, three million times the room, and plenty of time to spread out before the protectors died. The mutants would have it all their own way.”

“I don’t accept that you’re right,” Chmeee said quietly. “I do feel that you’ve missed a point. Granted that the protectors are almost certainly gone. Almost certainly. What if the Hindmost learns that this was their property, their home?”

“Oops. He’d run. With or without us.”

“Officially we have not penetrated the secret of the Ringworld’s construction. Agreed?”

“Yah.”

“Are we still looking for the Repair Center? The smell of tree-of-life might be deadly to you. You are too old to become a protector.”

“I wouldn’t want to. Is there a spectroscope in the lander?”

“Yes.”

“Tree-of-life doesn’t grow right without a soil additive: thallium oxide. Thallium must be more common in the galactic core than it is out here. Wherever the protectors spent a lot of their time, we’ll find thallium oxide for the plants. That’s how we’ll find the repair center. We’ll go in in pressure suits, if we ever get that far.”

Chapter 14 — The Scent Of Death

The Hindmost’s voice exploded at them as they reached the road. “… LANDER! CHMEEE, LOUIS, WHAT ARE YOU HIDING? HINDMOST CALLING THE LAND—”

“Stop! Tanj dammit, turn down the volume, you’ll blow our ears out!”

“Can you still hear me?”

“We can hear you fine,” said Louis. Chmeee’s ears had folded into pockets of fur. Louis was wishing he could do that. “The mountains must have blocked us.”

“And what was it you discussed while we were cut off?”

“Mutiny. We decided against it.”

A momentary pause; then “Very wise,” said the Hindmost. “I want your interpretation of this hologram.”

One of the screens showed a kind of bracket poking out from the rim wall. The picture was slightly blurred, and oddly lit: taken in vacuum, in sunlight and light reflected from the Ringworld landscape on the right. The bracket seemed to be of a piece with the rim wall itself, as if scrith had been stretched like taffy. The bracket held a pair of washers or doughnuts separated by their own diameter. Nothing else showed save the top of the rim wall. It was impossible to guess the scale.

“This was taken from the probe,” the puppeteer said. “I have inserted the probe into the rim transport system, as advised. It is accelerating to antispinward.”

“Yah. What do you think, Chmeee?”

“It might be a Ringworld attitude jet. It would not be firing yet.”

“Maybe. There are a lot of ways to design a Bussard ramjet. Hindmost, do you get anything in the way of magnetic effects?”

“No, Louis, the machine seems dormant.”

“The superconductor plague wouldn’t have touched it in vacuum. It doesn’t look damaged. The controls could be somewhere else, though. On the surface. Maybe they can be repaired.”

“You would have to find them first. In the Repair Center?”

“Yah.”

The road ran between swampland and stony highlands. They passed what looked like another chemical plant. They must have been seen; there was a deep-throated foghorn sound and a blast of steam from what might have been a chimney. Chmeee didn’t slow down.

They saw no more of the boxy vehicles.

Louis had seen pale glimmers passing slowly among the trees, far into the swamp. They moved as slowly as mist on water, or as ocean liners docking. Now, far ahead, a white shape moved free of the trees and toward the road.

From a vast white bulk the beast’s sense-cluster rose on a slender neck. Its jaw was at ground level; it dropped like a shovel blade, scooping up swamp water and vegetation as the beast cruised uphill on rippling belly muscles. It was bigger than the biggest dinosaur.

“Bandersnatch,” Louis said. What were they doing here? Bandersnatchi were native to Jinx. “Slow down, Chmeee, it wants to talk to us.”

“What of it?”

“They’ve got long memories.”

“What would they remember? Swamp dwellers, muck-eaters, without hands to make weapons. No.”

“Why not? Maybe they could tell us what bandersnatchi are doing on the Ringworld in the first place.”

“That is no mystery. The protectors must have stocked their maps in the Great Ocean with samples of the species they considered potentially dangerous.”

Chmeee was playing dominance games, and Louis didn’t like it. “What’s the matter with you? We could at least ask!”

The bandersnatch dwindled behind them. Chmeee snarled, “You avoid confrontation like a Pierson’s puppeteer. Questioning muck-eaters and savages! Killing sunflowers! The Hindmost brought us to this doomed structure against our wills, and you delay our vengeance to kill sunflowers. Will it matter to the Ringworld natives a year from now that Louis the God paused in his passing to pull weeds?”

“I’d save them if I could.”

“We can do nothing. It is the road builders we want. Too primitive to threaten us, advanced enough to know answers to questions. We will find an isolated vehicle and swoop down on it.”

In midafternoon Louis took over the flying.

The swamp became a river that arched away to spinward, wide of its original bed. The crude road followed the new river. The original bed ran more nearly to port, in careful S-curves, with an occasional stretch of rapids or waterfall. It was dry as bone, running into bone-dry desert. The swamp must have been a sea before it silted up.

Louis dithered, then followed the original bed.

“I think we’ve got the timing right,” he told Chmeee. “Prill’s people evolved long after the engineers were gone. Of all the intelligent races here, they were the most ambitious. They built the big, grand cities. Then that odd plague knocked out most of their machinery. Now we’ve got the Machine People, and they could be the same species. The Machine People built the road. They did it after the swamp formed. But I think the swamp formed after Prill’s people’s empire collapsed.

“So what I’m doing is looking for an old Prill People city. We could get lucky and find an old library or a map room.”

They had found cities scarce during the first expedition. Today they traveled for some hours without seeing anything except, twice, a cluster of tents, and once, a sandstorm the size of a continent.

The floating city was still ahead of them, edge on, hiding detail. A score of towers reared around the edge; inverted towers dropped from nearer the center.

The dry river ended in a dry sea. Louis cruised along the shore, twenty miles up. The sea bed was strange. It was quite flat, except where artfully spaced islands with fluted edges rose from the bottom.

Chmeee called, “Louis! Set us on autopilot!”

“What have you found?”

“A dredge.”

Louis joined Chmeee at the telescope.

He had taken it for part of one of the bigger islands. It was huge and flat, disc-shaped, the color of seabottom mud. Its top would have been below sea level. Its seamless rim was angled like the blade of a wood planer. The machine had stalled up against the island it had dredged from the sea bottom.

So this was how the Ringworld engineers had kept the sludge flowing into the spillpipes. It wouldn’t flow of itself; the sea bottoms were too shallow. “The pipe blocked,” Louis speculated. “The dredge kept going till it broke down, or till something cut the power — something like the superconductor plague. Shall I call the Hindmost?”

“Yes. Keep him satisfied… ”

But the Hindmost had bigger news.

“Observe,” he said. He ran a quick succession of holograms on one of the screens. A bracket poked up and out from the rim wall, with a pair of toroids mounted at its tip. Another bracket, seen from farther away; and in this picture a spill mountain showed at the foot of the rim wall. The spill mountain was half the size of the bracket. A third bracket showed. A fourth, with structures next to it. A fifth — “Hold it!” Louis cried. “Go back!”

The fifth bracket stayed on the screen for a moment. Its tip held nothing at all. Then the Hindmost flipped back to the fourth hologram.

It was somewhat blurred by the probe’s velocity. There was heavy lifting machinery anchored to the rim wall next to the bracket: a crude fusion generator; a powered winch; a drum and a hook floating unsupported below it. The cable depending from the drum must be invisibly thin, Louis thought. It could be shadow square wire.

“A repair team already at work? Uurrr. Are they mounting attitude jets or dismounting them? How many are mounted?”

“The probe will tell us,” the Hindmost said. “I direct your attention to another problem. Recall to your mind those toroids that circle the waist of the one intact Ringworld spacecraft. We surmise that they generate the electromagnetic scoop fields for Bussard ramjets.”

Chmeee studied the screen. “The Ringworld ships were all of the same design. I wondered why. You may be right.”

Louis said, “I don’t understand. What has—”

Two one-eyed snakes looked out of a screen at him. “Halrloprillalar’s species built part of a transportation system that would give them endless room to colonize and explore. Why didn’t they continue? All of the Ringworld was theirs through the rim transport system. Why would they make the effort to reach the stars?”

It made an ugly pattern. Louis didn’t want to believe it, but it fit too well. “They got the motors for free. They dismounted a few of the Ringworld attitude jets, built ships around them, and reached the stars. And nothing went obviously wrong. So they dismounted a few more. I wonder how many they used.”

“The probe will tell us in time,” the puppeteer said. “They seem to have left a few motors still mounted. Why did they not move the Ringworld back into position before the instability grew so great? Chmeee’s question is a good one. Are motors being remounted, or stolen to be used in ships so that a few more of Halrloprillalar’s race may escape?”

Louis’s laugh was bitter. “How does this sound? They left a few jets in place. Then came a plague that killed off most of their machinery. Some of them panicked. They took all the ships they had, and they built more ships in a hurry and dismounted most of the attitude jets to do it. They’re still at it. They’re leaving the Ringworld to its fate.”

Chmeee said, “Fools. They did it to themselves.”

“Did they? I wonder.”

“But this is just the possibility I find ominous,” said the puppeteer. “Would they not have taken as much of their civilization as they could move? Certainly they would have taken transmutation machinery.”

Oddly, Louis was not even tempted to laugh. But what answer could he make?

The kzin found an answer. “They would take all they could reach. Anything near the spaceport ledges. Anything near the rim wall, where the rim transport system was available. We must search inward, and we must search out the Repair Center. Any of Prill’s people found there would have been trying to save the Ringworld, not leave it.”

“Perhaps.”

Louis said, “It would help if we knew just when the plague started eating their superconductors.”

If he thought the Hindmost would flinch, he was wrong. The puppeteer said, “You will likely learn that before I do.”

“I think you know already.”

“Call me if you learn anything.” The snaky heads disappeared.

Chmeee was looking at him strangely, but he said nothing. Louis returned to the flight controls.

The terminator line was a vast shadow encroaching from spinward when Chmeee spotted the city. They had followed a sand-filled riverbed to port of the dry sea. The river forked here, and the city nestled in the fork.

Prill’s people had built tall, even where there was no obvious need. The city had not been wide, but it had been tall, until floating buildings smashed down into the lesser structures below. One slender tower still stood, but at a slant. It had driven itself like a spear into the lower levels. A road ran from port, along the outer edge of one branch of the dry river, then across a bridge so massively braced that it had to belong to the Machine People. Halrloprillalar’s people would have used stronger materials or would have floated it.

Chmeee said, “The city will have been looted.”

“Well, yes, given that someone built a road to do the looting. Why don’t you take us down anyway?”

“Your monkey curiosity?”

“Maybe. Just circle the tanj thing, give us a closer look.”

Chmeee dropped the lander fast enough to put them in free fall. The kzin’s fur was almost all grown out, a glossy and handsome orange coat, and a reminder of Chmeee’s new youth. Adolescence wasn’t helping his temper. Four Man-Kzin wars, plus a few “incidents”… Louis kept his mouth shut.

The lander surged under them. Louis waited until the savage weight left him, then began adjusting the views through the outside cameras. He saw it almost instantly.

A boxlike vehicle was parked beside the tilted tower. It could have held up to a dozen passengers. The motor housing at its rear should have been enough to lift a spacecraft… but this was a primitive people. He couldn’t guess what they’d be using to move the vehicle. He pointed and said, “We find an isolated vehicle and swoop down on it, right?”

“Right.” Chmeee let the lander settle. As he did, Louis studied the situation:

The tower had speared down into a squarish building; had smashed through the roof and three stories and possibly into a basement. It was the shell of the lesser building that held it upright. White puffs of steam or smoke jetted irregularly from two tower windows. Pale human shapes were dancing before the lower building’s big front entrance — dancing, or holding sprinting contests — and two were resting prone, though in unrestful positions…

Just before the single remaining wall of a collapsed building rose to block Louis’s view, it all jumped into his mind’s focus. The pale ones were trying to reach the entrance across a rubble-covered street. Someone in the tower was shooting at them.

The lander settled. Chmeee stood and stretched. “You seem to have your own luck, Louis. We can take the ones with the guns to be the Machine People. Our strategy will be to come to their aid.”

It seemed reasonable. “Do you know anything about projectile weapons?”

“If we assume chemical propellants, a portable weapon will not penetrate impact armor. We can enter the tower via flying belts. Carry stunners. We would not want to kill our future allies.”

They emerged into full night. Clouds had closed over the sky. Even so, Archlight glowed through in a faint broad band, and the floating city was a tight star-cluster to port. You couldn’t get lost.

Louis Wu was not comfortable. The impact armor was too stiff; the hood covered most of his face. The padded straps of the flying belt constricted his breathing, and his feet dangled. But nothing was ever again going to feel like an hour under the wire, and that was that. At least he felt relatively safe.

He hung in the sky and used light-amplified binocular goggles.

The attackers didn’t seem that formidable. They were quite naked and weaponless. Their hair was silver; their skin was very white. They were slender and pretty; even the men were more pretty than handsome, and beardless.

They kept to the shadows and the cover provided by fragments of broken buildings, except when one or two would sprint for the great doorway, zigzagging. Louis had counted twenty, eleven of them women. Five more were dead in the street. There might be others already in the building.

The defenders had stopped firing now. Perhaps they had run out of ammunition. They had been using two windows in the downward-slanting face of the tower, perhaps six stories up. Every window in the tower was broken.

He eased close to the larger floating shape of Chmeee. “We go in the other side, with lights at low intensity and wide aperture. I go first because I’m human. Right?”

“Right,” said Chmeee.

The belts lifted by scrith repulsion, like the lander. There were small thrusters in back. Louis circled round, checked to see Chmeee following, and floated in one of the windows at what he hoped was the right level.

It was one big room, and it was empty. The smell made him want to sneeze. There was web furniture with the webbing rotted away, and a long glass table, shattered. At the bottom of the sloping floor, a shapeless thing proved to be a pack with shoulder straps. So: they had been here. And the smell—

“Cordite,” Chmeee said. “Chemical propulsives. If they shoot at us, cover your eyes.” He moved toward a door. He flattened himself against the wall and flung the door suddenly open. A toilet, empty.

A bigger door hung open with the slant of the floor. With stunner in one hand and flashlight-laser in the other, Louis moved toward it. He felt a driving excitement drowning the fear.

Beyond the ornately carved wooden door, a broad circular staircase wound down into darkness. Louis shined his light down along loops of railing to where the spiral of stairs and the bottom of the building all crumpled in on itself. The light picked out a two-handed weapon with a shoulder butt, and a box that had spilled tiny golden cylinders; another weapon further down; a coat equipped with straps; more scraps of clothing on the lower stair; a human shape crumpled in the crushed bottom of the stairway — a naked man, seeming darker and more muscular than the attackers.

Louis’s excitement was growing unbearable. Was this really what he had needed all along? Not the droud and wire, but the risk of his life to prove its value! Louis adjusted his flying belt and dropped over the railing.

He fell slowly. There was nothing human on the stairs, but things had been dropped: anonymous clothing, weapons, boots, another shoulder pack. Louis continued dropping… and suddenly knew he’d found the right level. Quick adjustments to his flying belt sent him slamming through a doorway in pursuit of a smell radically different from what Chmeee had called cordite.

He was outside the tower. He barely avoided smashing into a wall; he was still inside the lower, crushed building. Somehow he’d dropped his light. He flicked up the amplification in the binocular goggles and turned right, toward light.

There was a dead woman in the great doorway: one of the attackers. Blood had pooled beneath a projectile wound in her chest. Louis felt a great sadness for her… and a driving urgency that made him fly right over her, through the doors and out.

The amplified Archlight was bright even through cloud cover. He had found the attackers, and the defenders too. They were paired off, pale, slender forms with shorter, darker ones who still wore bits of clothing, a boot or a head covering or a shirt ripped open. In the fury of their mating they ignored the flying man.

But one was not paired with anyone. As Louis stopped his flight she reached up and grasped his ankle, without insistence and without fear. She was silver-haired and very pale, and her finely chiseled face was beautiful beyond words.

Louis turned off the flying belt and dropped beside her. He took her in his arms. Her hands ran over his strange clothing, questing. Louis dropped the stunner, pulled off his vest and flying belt — his fingers were clumsy — his impact armor, his undersuit. He took her without finesse. His urgency was greater than any consideration for her. But she was as eager as he.

He was not aware of anything but himself and her. Certainly he didn’t know that Chmeee had joined them. He knew that, joltingly, when the kzin rapped his new love hard across the head with his laser. The furry alien hand sank its claws in her silver hair and pulled her head back, and pulled her teeth loose from Louis Wu’s throat.

Chapter 15 — The Machine People

The wind blew dust up Louis Wu’s nostrils; it whipped his hair in a storm around his face. Louis brushed it back and opened his eyes. The light was blinding-bright. His fumbling hands found a plastic patch on his neck, then binocular goggles covering his face. He pulled them loose.

He rolled away from the woman and sat up.

Now it was dim. Almost dawn: the terminator line split the world into light and dark. Louis ached in every muscle. He felt as if he’d been beaten. Paradoxically, he felt wonderful. For too many years he had used sex only rarely, and only as cover, because wireheads traditionally have no interest in such things. Last night his whole soul had been involved.

The woman? She was about Louis’s height, and on the stocky side of pretty. Not flat-chested, but not busty either. Her black hair was bound in a long braid, and there was a disconcerting fringe of beard along her jaw. She slept the sleep of exhaustion, and she’d earned it. They both had. Now he was beginning to remember. But his memories didn’t make much sense.

He’d been making love — no, he’d been head over heels in love with the pale, slender woman with the red lips. Seeing his blood on her mouth, feeling the sting in his neck, had left him only with a terrible sense of loss. He’d howled when Chmeee twisted her head around until her neck snapped. He’d fought when the kzin plucked him off the dead woman. The kzin had tucked him under one arm; he was still raging, still fighting, while Chmeee fished the medkit out of Louis’s vest and slapped a patch on his neck and tucked the medkit away again.

Then Chmeee had killed them, all the pretty silver-haired men and women, spearing them accurately through their heads with the brilliant ruby needle of his flashlight-laser. Louis remembered trying to stop him, and being thrown rolling across the broken pavement. He’d staggered to his feet, and seen someone else moving, and moved toward her. Her, the dark-haired woman, the only defender left alive. They’d moved into each other’s arms.

Why had he done that? And Chmeee had tried to get his attention… hadn’t he? Louis remembered a shrieking as of tigers at war.

“Pheromones,” he said. “And they looked so harmless!” He stood up and looked about him in sheer horror. The dead were all around him: the dark ones with wounded necks, the pale ones with blood on their mouths and black char marks in their silver hair.

The guns hadn’t been enough. What the vampires had was worse than a tasp. They put out a superstimulus cloud of pheromones, human scent-signals of sexual readiness. One of the vampires, or a pair, must have reached the tower. And the defenders had come out, running, shedding guns and clothing in a haste that sent one over the banister to his death.

But why, with the vampires dead, had he and the dark-haired woman… ?

The wind tossed at Louis’s hair. Yah. The vampires were dead, but he and the dark-haired woman were still in a cloud of pheromones. They’d mated in frenzy… ”If the wind hadn’t come up we’d still be Doing It. Yah. Now, where the tanj did I leave… everything?”

He found the impact armor and the flying belt. The undersuit was torn to shreds. What about the vest? He saw that the woman’s eyes were open. She sat up suddenly, with a horror in her eyes that Louis could well understand. He said to her, “I’ve got to have the vest because the translator’s in it. I hope Chmeee doesn’t frighten you off before I can—”

Chmeee. How had this looked to him?

Chmeee’s great hand engulfed Louis’s skull and twisted it backward. Louis clung to the woman with his body and his mind, and thrust, thrust, but his eyes were filled with that orange beast-face, and his ears with screaming insults. It was distracting…

Chmeee wasn’t in sight. Louis found the vest a good distance away, gripped in a vampire’s dead hand. He couldn’t find the stunner. By now he was really worried. Something ugly was thrusting out of his memory. He was running when he reached the place where they’d grounded the lander.

A chunk of rock too big for three men to lift was holding down a generous pile of black superconductor cloth. Chmeee’s parting gift. The lander was gone.

I’ll have to get over this sooner or later, Louis thought. Why not now? A friend had taught him this cantrip, this bit of magic for recovering from shock or grief. Sometimes it worked.

He was sitting on what had been a porch railing, though the porch now sat alone in a sand-covered walkway. He had donned his impact armor and the vest with all the pockets. He had put clothing between himself and a vast and lonely world. Not modesty, but fear.

That had used up all his ambition. Now he sat. Thoughts drifted aimlessly. He thought of a working droud as far away as the Earth from its moon, and a two-headed ally who would not risk landing here even to save Louis Wu. He thought of the Ringworld engineers and their idealized ecology, which had included nothing like mosquitoes or vampire bats; and his lips quirked into the beginning of a smile, then settled into a dead man’s expression, which is no expression at all.

He knew where Chmeee had gone. He smiled again to think how little good it did him. Had Chmeee told him that? No matter. Survival or the mating urge or vengeance on the Hindmost would all drive Chmeee in the same direction. But would any of these motives bring him back to rescue Louis Wu?

And he thought how little one death mattered, with the Ringworld’s trillions all doomed to intimate contact with their sun.

Well, Chmeee might return. Louis ought to get off his butt and do something about reaching the floating city. They’d been headed there; Chmeee would expect to find him there, if some whim brought the kzin back for the ally who had failed him so badly. Or Louis might actually learn something valuable. Or… he’d have to survive somewhere in the year or two left to him. I’ll have to get over this sometime. Why not now?

Somebody yelled.

The black-haired woman had dressed herself in shorts and shirt and a backpack. She held a projectile weapon at her side, pointed at Louis Wu. With her other arm she gestured and yelled again.

Vacation was over. Louis became acutely aware that his hood was around his neck. If she tried a head shot — well, she might just give him time to pull the hood over his face, and then it wouldn’t matter if she fired or not. The impact suit would stop the projectiles while he ran. What he really needed was the flying belt. Or did he?

“Okay,” said Louis, and he smiled and raised his hands to the sides. What he really needed was an ally. With one hand he reached slowly into his vest, withdrew the translator, clipped it just under his throat. “This will talk for us, as soon as it learns to.”

She motioned with the gun: Go ahead of me.

Louis walked as far as the flying belt, then stooped and picked it up, without jerky motions. Thunder cracked. A stone six inches from Louis Wu’s foot jumped wildly away. He dropped the harness and stepped back.

Tanj, she wasn’t talking! She’d decided he couldn’t speak her language, and that was that. How would the translator learn anything?

With his hands in the air, he watched her fiddle one-handed with the flying belt while she kept the gun more or less on him. If she touched the wrong controls, he’d lose the belt and the cloth too. But she set the belt down, studied Louis’s face a moment, then stepped back and gestured.

Louis picked up the flying belt. When she gestured toward her vehicle, he shook his head. He went to where Chmeee had left an acre or so of superconductor cloth, weighted down by a boulder far too heavy to move.

The gun never left him as he strapped the harness around the rock and activated the flying belt. He wrapped his arms around the rock — and the harness, for fear it would slip — and lifted. The rock came up. He turned full around and let go. It settled slowly to the ground.

Was that respect in her eyes? Was it for his technology or his strength? He turned off the belt, picked up it and the superconductor cloth, and moved ahead of her to her vehicle. She opened double doors in its side. He set his burden down and looked around.

Couches around three sides; a tiny stove in the center, and a hatch in the roof for a smoke hole. Stacks of baggage behind the rear seat. Another couch in front, facing forward.

He backed out. He turned back toward the tower, took one step forward, and looked at her. She got the idea. She dithered, then gestured him on.

The dead were beginning to smell. He wondered if she would bury or burn them. But she walked among the bodies without stopping. It was Louis who stopped, to probe with his fingers in a woman’s silver hair.

There was too much hair, too little skull. Beautiful she was, but her brain was smaller than a human brain. He sighed and went on.

The woman followed him through the shell of the lower building, into the tower’s spiral staircase, and down. A dead man of her species lay broken in the crushed basement, and the flashlight-laser was next to him. When he glanced back at the woman, he saw tears in her eyes.

He reached for the flashlight-laser and she fired past him. The ricochet thumped him on the hip, and he shied violently inside the suddenly rigid shell. He backed against the shattered wall while she picked up the device.

She found the switch, and light jumped around them in a wide beam. She found the focus; the beam narrowed. She nodded and dropped the device in her pocket.

On their walk back to the vehicle Louis casually pulled the impact-suit hood over his face, as if the sunlight were too bright. She might have all she wanted from Louis Wu, or she might be short of water, or she might not want his company.

She didn’t shoot him. She climbed into the car and locked the doors, with a key. For an instant Louis saw himself marooned with no water and no tools. But she gestured him close to the right-hand window, where the driving controls were. She began to show him how to drive.

It was the breakthrough Louis had hoped for. He repeated the words she called through the window, and added his own words. “Steering ring. Turn. Activator. Key. Throttle. Retrothrottle.” She was pretty good with gestures. A hand zipping through air plus a finger tracing a needle’s path were “airspeed gauge.”

It startled her when the translator began talking back to her. She let the language lesson continue for a bit. Then she unlocked the door, backed across the seat with the gun ready, and said, “Get in. Drive.”

The machine was noisy and balky. It translated every little bump directly to the driver’s couch until Louis learned to steer around cracks in the road, rubble, or drifts of sand. The woman watched him silently. Did she have no curiosity? It occurred to him that she had lost a dozen companions to the vampires. Under the circumstances she was functioning well enough.

Presently she said, “I am Valavirgillin.”

“I am Louis Wu.”

“Your devices are strange. The speaker, the lifter, the variable light — what more have you?”

“Tanj dammit! I left the eyepieces.”

She pulled the binocular goggles out of a pocket. “I found these.”

She may have found the stunner too. Louis didn’t ask. “Good. Put them on and I’ll show you how they work.”

She smiled and shook her head. She must be afraid he’d jump her. She asked, “What were you doing in the old city? Where did you find these things?”

“They are mine. I brought them from a far star.”

“Do not mock me, Louis Wu.”

Louis looked at her. “Did the people who built the cities have such things?”

“They had things that speak. They could raise buildings in the air; why not themselves?”

“What of my companion? Have you found his like on the Ringworld?”

“He seemed monstrous.” She flushed. “I had no chance to study him.”

No, she’d been distracted. Nuts. “Why do you point a gun at me? The desert is enemy to both of us. We should help each other.”

“I have no reason to trust you. Now I wonder if you are mad. Only the City Builders traveled between the stars.”

“You are mistaken.”

She shrugged. “Must you drive so slowly?”

“I need practice.”

But Louis was getting the hang of it. The road was straight and not too rough, and there was nothing coming at him. There were drifts of sand across the road. Valavirgillin had told him not to slow for these.

And he was moving at a fair clip toward his destination. He asked, “What can you tell me about the floating city?”

“I have never been there. The children of the City Builders use it. They no longer build, nor do they rule, but our custom is that they keep the city. They have many visitors.”

“Tourists? People who go only to see the city?”

She smiled. “For that and other reasons. One must be invited. Why must you know these things?”

“I have to get to the floating city. How far may I drive with you?”

Now she laughed. “I think that you will not be invited there. You are not famous nor powerful.”

“I’ll think of something.”

“I go as far as the school at River’s Return. There I must tell them what happened.”

“What did happen? What were you doing there in the desert?”

She told him. It wasn’t easy. There were gaps in the translator’s vocabulary. They worked around the gaps and filled them in.

The Machine People ruled a mighty empire.

Traditionally an empire is a cluster of nearly independent kingdoms. The various kingdoms must pay taxes, and they follow the emperor’s commands as regards war, banditry control, maintenance of communication, and sometimes an official religion. Otherwise they follow their own customs.

And that was doubly true within the Machine Empire, where, for instance, the way of life of a herd-keeping carnivore was in competition with the life style of the Grass People; was useful to the traders, who bought the carnivores’ tooled leather goods; and was irrelevant to the ghouls. In some territories many species worked in cooperation, and all allowed free passage to the ghouls. The various species followed their own customs because they were built to.

Ghoul was Louis Wu’s word. Valavirgillin called them something like Night People. They were the garbage collectors and the morticians too, which was why Valavirgillin had not buried her dead. The ghouls had speech. They could be taught to give last rites in the local hominid religions. They formed an information source for the Machine People. Legend said that they had done the same for the City Builders when the City Builders ruled.

According to Valavirgillin, the Machine Empire was an empire of trade, and it taxed only its own merchants. The more she talked, the more exceptions Louis found. The kingdoms maintained the roads that linked the empire, if their people were capable of it, which (for instance) the tree-living Hanging People were not. The roads marked the borders between territories held by different species of hominid. Wars of conquest across the roads were forbidden; and so the roads prevented wars (sometimes!) merely by existing.

The empire had the power to draft armies to battle bandits and thieves. The large patches of land the empire took for trading posts tended to become full colonies. Because roads and vehicles linked the empire, the kingdoms thereof were required to distill chemical fuel and hold it available. The empire purchased mines (by forced sale?), mined its own ore, and leased the right to manufacture machinery according to the empire’s specifications.

There were schools for traders. Valavirgillin and her companions were students and a teacher from the school at River’s Return. They had set out on a field trip to a trade center bordering the jungle lands of the Hanging People — brachiators, Louis gathered, who traded in nuts and dried fruit — and the Herders, carnivores who dealt in leather goods and handicrafts. (No, they were not small and red. A different species.) They had veered for a side trip to an ancient desert city.

They had not expected vampires. Where would vampires find water in this desert? How would they get there? Vampires were almost extinct except for—

“Except for what? I missed something.”

Valavirgillin blushed. “Some older people keep toothless vampires for — for the purpose of rishathra. That may be how it happened. A tame pair escaped somehow, or a pregnant female.”

“Vala, that’s disgusting.”

“It is,” she agreed coolly. “I never heard anyone admit to keeping vampires himself. Where you come from, is there nothing that some do that others find shameful?”

That shot struck home. “I’ll tell you about current addiction sometime. Not now.”

She studied him over the metal snout of her weapon. Despite that fringe of black beard along her jaw, she looked human enough… but widened. Her face was almost perfectly square. Louis was having trouble reading her face. That was predictable; the human face has evolved as a signaling device, and Vala’s evolution diverged from his.

He asked, “What will you do next?”

“I must report the deaths… and give over the artifacts from the desert city. There is a bounty, but the empire claims City Builder artifacts.”

“I tell you again that they are mine.”

“Drive.”

The desert was showing patches of greenery, and a shadow square sliced the sun, when Valavirgillin bade him stop. He was glad to. He was exhausted with the battering of the road and the endless task of keeping the vehicle aimed.

Vala said, “You will -- dinner.”

They were used to gaps in the translation. “I missed that word.”

“You contrive to heat food until it can be eaten. Louis, can’t you -- ?”

“Cook.” She wasn’t likely to have frictionless pans and a microwave oven, was she? Or measuring cups, refined sugar, butter, any spice he could recognize — “No.”

“I will cook. Make me a fire. What do you eat?”

“Meat, some plants, fruit, eggs, fish. Fruit I can eat not cooked.”

“Just like my people, except for fish. Good. Step out and wait.”

She locked him out of the vehicle, then crawled into the back. Louis stretched aching muscles. The sun was a blazing sliver, still dangerous to look at, but the desert was growing dark. A broad band of worldscape blazed to antispinward. There was brownish scrub grass around him now, and a clump of tall, dry trees. One tree was white and dead-looking.

She crawled out into the air. She tossed a heavy thing at Louis’s feet. “Cut wood and build a fire.”

Louis picked it up: a length of wood with a wedge of crude iron fixed to one end. “I hate to sound stupid, but what is it?”

She named it. “You swing the sharp edge against the trunk till the tree falls down. See?”

“Ax” Louis remembered the war axes in the museum on Kzin. He looked at the ax, then the dead tree… and suddenly he’d had enough. He said, “It’s getting dark.”

“Do you have trouble seeing at night? Here.” She tossed him the flashlight-laser.

“That dead tree good enough?”

She turned, giving him a nice profile, the gun turning with her. Louis adjusted the light to narrow beam, high intensity. He flipped it on. A bright thread of light licked past her. Louis flicked it across her weapon. The weapon spurted flame and fell apart.

She stood there with her mouth open and the two pieces in her hands.

“I am perfectly willing to take suggestions from a friend and ally,” he told her. “I’m sick of taking orders. I got plenty of that from my furry companion. Let’s be friends.”

She dropped what she was holding and raised her hands.

“You’ve got more bullets and more guns in the back of the vehicle. Arm yourself.” Louis turned away. He sliced his beam down the dead tree in zigzag fashion. A dozen logs fell burning. Louis strolled over and kicked the logs into a tighter pile around the stump. He played the laser into their midst and watched the fire catch.

Something thumped him between the shoulder blades. For an instant the impact suit went stiff. He heard a single crack of thunder.

Louis waited for a bit, but the second shot didn’t come. He turned and walked back to the vehicle and Vala. He said to her, “Don’t you ever, ever, ever do that again.”

She looked pale and frightened. “No. I won’t.”

“Shall I help you carry your cooking things?”

“No, I can… Did I miss you?”

“No.”

“Then how?”

“One of my tools saved me. I brought it a thousand times the distance light travels in a falan, and it’s mine.”

She made a kind of arm-flapping gesture and turned away.

Chapter 16 — Strategies Of Trade

There was a plant that grew along the ground like so many links of green-and-yellow-striped sausage, with rootlets sprouting between the links. Valavirgillin sliced some of these into a pot. She added water, then some seed pods from a sack in the vehicle. She set the pot on the burning logs.

Tanj, Louis could have done that himself. Dinner was going to be crude.

The sun was entirely gone now. A tight cluster of stars to port must be the floating city. The Arch swooped up the black sky in horizontal bands of glowing blue and white. Louis felt that he was on some tremendous toy.

“I wish I had some meat,” Vala said.

Louis said, “Give me the goggles.”

He turned away from the fire before he put the goggles on. He turned up the light amplification. The pairs of eyes that had been watching from beyond the reach of the firelight resolved. Louis was glad he hadn’t fired at random. Two large shapes and a smaller one were a family of ghouls.

But one bright-eyed shadow was small, and furry. Louis snipped it headless with the long bright thread from his flashlight-laser. The ghouls flinched. They whispered among themselves. The female started toward the dead animal, but stopped to give Louis precedence. Louis picked up the body and watched her back away.

The ghouls seemed diffident enough. But their place in the ecology was very secure. Vala had told him what happened when a people went to the great effort of burying or burning their dead. The ghouls attacked the living. They owned the night. With magic gleaned from scores of local religions, they were said to be able to turn invisible. Even Vala half believed it.

But they weren’t bothering Louis. Why would they? Louis would eat the furry beast, and one day Louis himself would die, and the ghouls would claim their due.

While they watched him, he examined the creature: rabbitlike, but with a long, flat-ended tail and no forepaws at all. Not a hominid. Good.

When he looked up, there was a faintly glowing violet flame far to port.

Holding his breath, holding himself very still, Louis raised both the light amplification and the magnification. Even his pulse in his temples was blurring the picture now, but he knew what he saw. The magnified flame was eye-hurting violet, and it fanned out like a rocket firing in vacuum. Its bottom was clipped off by a straight black line: the edge of the portward rim wall.

He lifted the goggles. Even after his eyes adjusted, the violet flame was barely visible, but it was still there. Tenuous… and tremendous.

Louis returned to the fire and dropped the beast at Vala’s feet. He walked into the darkness to starboard and donned the goggles again.

The flame to starboard showed much larger, but of course that rim wall was much closer.

Vala skinned the little furry beast and dropped it into the pot without removing the entrails. When she had finished, Louis led her by the arm into the darkness. “Wait a little, then tell me if you see a blue flame far away.”

“Yes, I see it.”

“Do you know what it is?”

“No, but I think my father does. There was something he wouldn’t talk about, the last time he came back from the city. There are more. Turn your eyes to the base of the Arch to spinward.”

A daylit, blue-and-white horizontal stripe was bright enough to make him squint. Louis covered it with the edge of his hand… and now, with the goggles to help, he could make out two small candle flames on the rims of the Arch, and two above them, tinier yet.

Valavirgillin said, “The first appeared seven falans ago, near the base of the spinward Arch. Then more to spinward, and these large flames to port and starboard, then more small ones on the antispinward Arch. Now there are twenty-one. They only show for two days each turn, when the sun is brightest.”

Louis heaved a gusty sigh of relief.

“Louis, I don’t know what it means when you do that. Are you angry or frightened or relieved?”

“I don’t know either. Let’s say relieved. We’ve got more time than I thought.”

“Time for what?”

Louis laughed. “Haven’t you had enough of my madness yet?”

She bridled. “After all, I can choose whether to believe you or not!”

Louis got mad. He didn’t hate Valavirgillin, but she was a thorny character, and she had already tried to kill him once. “Fine. If this ring-shaped structure you live on is left to itself, it will brush against the shadow squares — the objects that cover the sun when night comes — in five or six falans. That will kill everything. There won’t be anything left alive when you brush against the sun itself—”

She screamed, “And you sigh with relief?”

“Easy, take it easy. The Ringworld is not being left alone. Those flames are motors for moving it. We’re almost at the closest point to the sun, and they’re using braking thrust — they’re firing inward, sunward. Like this.” He sketched the situation for her in the dirt with a pointed stick. “See? They’re holding us back.”

“You say now that we will not die?”

“The motors may not be strong enough for that. But they’ll hold us back. We could have ten or fifteen falans.”

“I do hope you are mad, Louis. You know too much. You know that the world is a ring, and that is secret.” She shrugged as one shifts a heavy weight. “Yes, I have had enough of it. Will you tell me why you have not suggested rishathra?”

He was surprised. “I would have thought you’d had enough of rishathra to last a lifetime.”

“That is not funny. Rishathra is the way to seal a truce!”

“Oh. All right. Back to the fire?”

“Of course, we need light.”

She pulled the pot a little back from the flame, to cook more slowly. “We must discuss terms. Will you agree not to harm me?” She sat down across from him on the ground.

“I agree not to harm you unless I am attacked.”

“I make you the same concession. What else do you want from me?”

She was brisk and matter-of-fact, and Louis fell into the spirit of the thing. “You will transport me as far as you can, subject to your own needs. I expect that’s as far as, ah, River’s Return. You will treat the artifacts as mine. You will not turn them or me over to any authority. You will give me advice, to the best of your knowledge and ability, that will get me into the floating city.”

“What can you offer in return?”

Here now, wasn’t this woman utterly at Louis Wu’s mercy? Well, never mind. “I will attempt to find out if I can save the Ringworld,” he said, and was somewhat astonished to realize that it was what he most desired. “If I can, I will, no matter what the cost. If I decide the Ringworld can’t be saved, I will try to save myself, and you if it’s convenient.”

She stood. “A promise, empty of meaning. You offer me your madness as if it held real value!”

“Vala, haven’t you dealt with madmen before?” Louis was amused.

“I have never dealt with even sane aliens! I am only a student!”

“Calm down. What else can I offer you? Knowledge? I’ll share my knowledge freely, such as it is. I know how the City Builders’ machines failed, and who caused it.” It seemed safe to assume that the City Builders were Halrloprillalar’s species.

“More madness?”

“You’ll have to decide that for yourself. And… I can give you my flying belt and eyepieces when I’m through with them.”

“When is that likely to be?”

“When and if my companion returns.” The lander held another flying belt and set of goggles, intended for Halrloprillalar. “Or let them be yours when I die. And I can give you half my store of cloth now. Strips of it would let you repair some of the City Builders’ old machines.”

Vala thought it over. “I wish I were more skilled. Well, then, I agree to all of your requirements.”

“I agree to yours.”

She began to take off her clothes and jewelry. Slowly, seemingly titillatingly… until Louis saw what she was doing: stripping herself of all possible weapons. He waited until she was quite naked, then imitated her, dropping the flashlight-laser and goggles and the pieces of impact armor some distance from her, adding even his chronometer.

They made love, then, but it wasn’t love. The madness of last night was gone with the vampires. She asked his preferred technique, then insisted, and he chose the missionary position. It was too much a formality. Perhaps it was meant to be. Afterward, when she went to stir the cooking pot, he was careful that she didn’t get between him and his weapons. It felt like that kind of situation.

She came back to him, and he explained that his kind could make love more than once.

He sat cross-legged with Vala in his lap, her legs closed tight around his hips. They stroked each other, aroused each other, learned each other. She liked having her back scratched. Her back was muscular, her torso wider than his own. A strip of her hair ran all the way down her spine. She had fine control of the muscles of her vagina. The fringe of beard was very soft, very fine.

And Louis Wu had a plastic disc under the hair at the crown of his head.

They lay in each other’s arms, and she waited.

“Even if you don’t have electricity, you must know about it,” Louis said. “The City Builders used it to run their machines!”

“Yes. We can make electricity from the flow of a river. Tales tell that endless electricity came from the sky before the fall of the City Builders.”

Which was accurate enough. There were solar power generators on the shadow squares, and they beamed the power to collectors on the Ringworld. Naturally the collectors used superconducting cables, and naturally they had failed.

“Well, then. If I let a very fine wire down into my brain in the right place — which I did — then a very little bit of electric power will tickle the nerves that register pleasure.”

“What is it like?”

“Like getting drunk without the hangover or the dizziness. Like rishathra, or real mating, without needing to love anyone but yourself and without needing to stop. But I stopped.”

“Why?”

“An alien had my electric source. He wanted to give me orders. But I was ashamed before that.”

“The City Builders never had wires in their skulls. We would have found them when we searched the ruined cities. Where is this custom practiced?” she asked. Then she rolled away from him and stared at him in horror.

It was the sin he regretted most often: not keeping his mouth shut. He said, “I’m sorry.”

“You said strips of that cloth would — What is that cloth?”

“It conducts electric current and magnetic fields with no loss. Superconductor, we call it.”

“Yes, that was what failed the City Builders. The… superconductor rotted. Your cloth will rot too, will it not? How long?”

“No. It’s a different kind.”

She screamed it at him. “How do you know that, Louis Wu?”

“The Hindmost told me. The Hindmost is an alien who brought us here against our will. He left us with no way home.”

“This Hindmost, he took you as slaves?”

“He tried to. Humans and kzinti, we make poor slaves.”

“Is his word good?”

Louis grimaced. “No. And he took the superconductor cloth and wire when he fled his world. He didn’t have time to make it. He must have known where it was, in storage. Like the other things he brought, the stepping discs: it must have been readily available.” And he knew instantly that something was wrong, but it took him a moment to know what it was.

The translator had stopped speaking too soon.

Then it spoke with a very different voice. “Louis, is it wise to, tell her these things?”

“She guessed part of it,” Louis said. “She was about to blame me for the Fall of the Cities. Give me back my translator.”

“Can I allow you this ugly suspicion? Why would my people perform so malicious an act?”

“Suspicion? You son of a bitch.” Vala knelt watching him with big eyes, listening to him talk to himself in gibberish. She couldn’t hear the Hindmost’s voice in his earphones. Louis said, “They kicked you out as Hindmost and you ran. You grabbed what you could and ran. Stepping discs and superconductor cloth and wire and a ship. Discs were easy. You must make them by the million. But where would you find superconductor cloth just waiting for you? And you knew it wouldn’t rot on the Ringworld!”

“Louis, why would we do such a thing?”

“Trade advantage. Give me back my translator!”

Valavirgillin got up. She pulled the pot a little out from the fire, stirred it, tasted. She disappeared toward the vehicle and returned with two wooden bowls, which she filled with a dipper.

Louis waited uneasily. The Hindmost could leave him stranded, with no translator. Louis wasn’t good with languages…

“All right, Louis. It wasn’t planned this way, and it happened before my time. We were searching for a way to expand our territory with minimal risk. The Outsiders sold us the location of the Ringworld.”

The Outsiders were cold, fragile beings who roamed throughout the galaxy in slower-than-light craft. They traded in knowledge. They might well have known of the Ringworld, and sold the information to puppeteers, but… ”Wait a minute. Puppeteers are afraid of spaceflight.”

“I overcame that fear. If the Ringworld had proved suitable, then one spaceflight in an individual’s lifetime is no great risk. We would have flown in stasis, of course. From what the Outsiders told us, and from what we learned via telescopes and automatic probes, the Ringworld seemed ideal. We had to investigate.”

“An Experimentalist faction?”

“Of course. Still, we hesitated to contact so powerful a civilization. But we analyzed Ringworld superconductors through laser spectroscopy. We made a bacterium that could feed on it. Probes seeded the superconductor plague across the Ringworld. You guessed as much?”

“That much, yah.”

“We were to follow with trading ships. Our traders would come opportunely to the rescue. They would learn all we needed to know, and gain allies too.” Clear and musical, the puppeteer’s voice held no trace of guilt, nor even embarrassment.

Vala set the bowls down and knelt across from him. Her face was in shadow. From her viewpoint the translation could not have ended at a worse moment.

Louis said, “Then the Conservatives won an election, I take it.”

“Inevitable. A probe found attitude jets. We knew of the Ringworld’s instability, of course, but we hoped for some more sophisticated means of dealing with it. When the pictures were made public, the government fell. We have had no chance to return to the Ringworld until—”

“When? When did you spread the plague?”

“Eleven hundred and forty years ago by Earth time. The Conservatives ruled for six hundred years. Then the threat of the kzinti put Experimentalists back in power. When the time seemed opportune, I sent Nessus and his team to the Ringworld. If the structure had survived for eleven hundred years after the fall of the culture that kept it in repair, it would have been worth investigating. I could have sent a trade and rescue team. Unfortunately—”

Valavirgillin had the flashlight-laser in her lap, pointed at Louis Wu.

“—unfortunately the structure was damaged. You found meteor holes and landscape eroded down to the scrith. It now seems—”

“This is an emergency. This is an emergency.” Louis held his voice steady. How had she done that? He’d watched her kneel with a steaming bowl of stew in each hand. Could the thing have been taped to her back? Skip it. At least she hadn’t fired yet.

“I hear you,” said the Hindmost.

“Can you turn off the flashlight-lasers by remote control?”

“I can do better than that. I can explode it, killing him who holds it.”

“Can’t you just turn it off?”

“No.”

“Then give me back my translator function tanj quick. Testing—”

The box spoke Machine People speech. Vala answered immediately. “Whom or what were you talking to?”

“To the Hindmost, the being who brought me here. May I assume that I have not yet been attacked?”

She hesitated before answering. “Yes.”

“Then our agreements are still in force, and I’m still gathering data with intent to save the world. Do you have reason to doubt that?” The night was warm, but Louis felt very naked.

The dead eye of the flashlight-laser remained dead. Vala asked, “Did the Hindmost’s race cause the Fall of the Cities?”

“Yes.”

“Break off negotiation,” Vala ordered.

“He’s got most of our data-gathering instruments.”

Vala thought it through, and Louis remained still. Two pairs of eyes glowed close behind her in the dark. Louis wondered how much the ghouls heard with those goblin ears, and how much they understood.

“Use them, then. But I want to hear what he says,” said Vala. “I have not even heard his voice. He may be only your imagination.”

“Hindmost, you heard?”

“I did.” Louis’s earplugs were speaking Interworld, but the box at his throat spoke Valavirgillin’s own tongue. Well and good. “I heard your promise to the woman. If you can find a way to stabilize this structure, do so.”

“Sure, your people could use the room.”

“If you should stabilize the Ringworld with help from my equipment, I want credit. I may want to ask a reward.”

Valavirgillin snarled and choked off a reply. Louis said quickly, “You’ll get the credit you deserve.”

“It was my government, under my leadership, that tried to bring aid to the Ringworld eleven hundred years after the damage was done. You will vouch for that.”

“I will, with reservations.” Louis was speaking for Vala’s benefit. He told her, “By our agreements, you regard what you’re holding as my property.”

She flipped him the flashlight-laser. He set it aside, and felt himself sagging with relief, or fatigue, or hunger. No time. “Hindmost, tell us about the attitude jets.”

“Bussard ramjets mounted on brackets on the rim wall, regularly spaced, three million miles apart. We should find two hundred mountings on each rim wall. In operation each would collect the solar wind over a four- to five-thousand-mile radius, compress it electromagnetically until it undergoes fusion, and blast it back in rocket fashion, in braking mode.”

“We can see some of them firing. Vala says there are… twenty-one operating?” Vala nodded. “That’s 95 percent of them missing. Futz.”

“It seems likely. I have holos of forty mountings since we last spoke, and all were empty. Shall I compute the thrust delivered with all jets firing?”

“Good.”

“I expect there are not enough jets mounted to save the structure.”

“Yah.”

“Would the Ringworld engineers have installed an independently operating stabilizing system?”

Pak protectors didn’t think that way, did they? They tended to have too much confidence in their ability to improvise. “Not likely, but we’ll keep looking. Hindmost, I’m hungry and sleepy.”

“Is there more that must be said?”

“Keep a watch on the attitude jets. See what’s functional and get their thrust.”

“I will.”

“Try to contact the floating city. Tell—”

“Louis, I can send no message through the rim wall.”

Of course not, it was pure scrith. “Move the ship.”

“It would not be safe.”

“What about the probe?”

“The orbiting probe is too distant to send on random frequencies.” With vast reluctance the Hindmost added, “I can send messages via the remaining probe. I should send it over the rim wall in any case, to refuel.”

“Yah. First set it on the rim wall for a relay station. Try to reach the floating city.”

“Louis, I had trouble homing on your translator. I trace the lander nearly twenty-five degrees to antispinward of your position. Why?”

“Chmeee and I split our efforts. I’m headed for the floating city. He’s headed for the Great Ocean.” It should be safe to say that much.

“Chmeee doesn’t answer my broadcasts.”

“Kzinti make poor slaves. Hindmost, I’m tired. Call me in twelve hours.”

Louis took up his bowl and ate. Valavirgillin had used nothing in the way of spices. The boiled meat and roots didn’t excite his taste buds. He didn’t care. He licked the bowl clean and retained just enough sense to take an allergy pill. They crawled into the vehicle to sleep.

Chapter 17 — The Moving Sun

The padded bench was a poor substitute for sleeping plates, and it was jolting under him. Louis was stiff tired. He slept and was shaken awake, slept and was shaken awake…

But this time it was Valavirgillin shaking his shoulders. Her voice was silkily sarcastic. “Your servant dares to break your well-earned rest, Louis.”

“Uh. Okay. Why?”

“We have come a good distance, but here there are bandits of the Runner breed. One of us must ride as gunner.”

“Do Machine People eat after waking?”

She was disconcerted. “There is nothing to eat. I am sorry. We eat one meal, then sleep.”

Louis donned impact armor and vest. Together he and Vala manhandled a metal cover into place over the stove. Louis stood on it and found that his head and armpits rose through the smoke hole. He called down, “What do Runners look like?”

“Longer legs than mine, big chests, long fingers. They may carry guns stolen from us.”

The vehicle lurched into motion.

They were driving through mountainous country, through dry scrub vegetation, chaparral. The Arch was visible by daylight, if you remembered to look; otherwise it faded into the blue of the sky. In the haze of distance Louis could make out a city floating on air in fairy-tale fashion.

It all looked so real, he thought. Two or three years from now it might as well have been some madman’s daydream.

He fished the translator out of his vest. “Calling the Hindmost. Calling the Hindmost… ”

“Here, Louis. Your voice holds an odd tremor.”

“Bumpy ride. Any news for me?”

“Chmeee still does not answer calls, nor do the citizens of the floating city. I have landed the second probe in a small sea, without incident. I doubt that anyone will discover it on a sea bottom. In a few days Hot Needle of Inquiry will have full tanks.”

Louis declined to tell the Hindmost about the Sea People. The safer the puppeteer felt, the less likely he was to abandon his project, the Ringworld, and his passengers. “I meant to ask. You’ve got stepping discs on the probes. If you sent a probe for me, I could just step through to Needle. Right?”

“No, Louis. Those stepping discs connect only to Needle’s fuel tank, through a filter that passes only deuterium atoms.”

“If you took off the filter, would they pass a man?”

“You would still end in the fuel tank. Why do you ask? At best you might save Chmeee a week of travel.”

“That could be worth doing. Something might come up.” Now, why was Louis Wu hiding the rogue kzin’s defection? Louis had to admit that he found the incident embarrassing. He really didn’t want to talk about it… and it might make a puppeteer nervous. “See if you can work out an emergency procedure, just in case we need it.”

“I will. Louis, I locate the lander a day short of reaching the Great Ocean. What does Chmeee expect to find there?”

“Signs and wonders. Things new and different. Tanj, he wouldn’t have to go if we knew what was there.”

“But of course,” the puppeteer said skeptically. He clicked off, and Louis pocketed the translator. He was grinning. What did Chmeee expect to find at the Great Ocean? Love and an army! If the map of Jinx had been stocked with bandersnatchi then what of the map of Kzin?

Sex urge or self-defense or vengeance — any one of these would have driven Chmeee to the map of Kzin. For Chmeee safety and vengeance went together. Unless Chmeee could dominate the Hindmost, how could he return to known space?

But even with an army of kzinti, what could Chmeee expect to do against the Hindmost? Did he think they’d have spacecraft? Louis thought he was in for a disappointment.

But there would certainly be female kzinti.

There was something Chmeee could do about the Hindmost. But Chmeee probably wouldn’t think of it, and Louis couldn’t tell him now. He wasn’t sure he wanted to, yet. It was too drastic.

Louis frowned. The puppeteer’s skeptical tone was worrying. How much had he guessed? The alien was a superb linguist; but because he was an alien, such nuances would never creep into his voice. They had to be put there.

Time would tell. Meanwhile, the dwarf forest had grown thick enough to hide crouching men. Louis kept his eyes moving, searching clumps and folds of hillside ahead. His impact armor would stop a sniper’s bullet, but what if a bandit shot at the driver? Louis could be trapped in mangled metal and burning fuel.

He kept his full attention on the landscape.

And presently he saw that it was beautiful. Straight trunks five feet tall sprouted enormous blossoms at their tips. Louis watched a tremendous bird settle into a blossom, a bird similar to a great eagle except for the long, slender spear of a beak. Elbow root, a larger breed than he’d seen on his first visit, some ninety million miles from here, flourished in a tangle of randomly placed fences. Here grew the sausage plant they’d eaten last night. There, a sudden cloud of butterflies, at this distance looking much like Earth’s butterflies.

It all looked so real. Pak protectors wouldn’t build anything flimsy, would they? But the Pak had had vast faith in their works, and in their ability to repair anything, or even to create new widgets from scratch.

And all of his speculation was based on the word of a man seven hundred years dead: Jack Brennan the Belter, who had known the Pak only through one individual. The tree-of-life had turned Brennan himself into a protector-stage human — armored skin, second heart, expanded braincase, and all. That might have left him insane. Or Phssthpok might have been atypical. And Louis Wu, armed with Jack Brennan’s opinions on Phssthpok the Pak, was trying to think like something admittedly more intelligent than himself.

But there had to be a way to save all this.

Chaparral gave way to sausage-plant plantations to spinward, rolling hills to antispinward. Presently Louis saw his first refueling station ahead. It was a major operation, a chemical factory with the beginnings of a town growing around it.

Vala called him down from his perch. She said, “Close the smoke hole. Stay in the van and do not be seen.”

“Am I illegal?”

“You are uncustomary. There are exceptions, but I would need to explain why you are my passenger. I have no good explanation.”

They pulled up along the windowless wall of the factory. Through the window Louis watched Vala dickering with long-legged, big-chested people. The women were impressive, with large mammaries on large chests, but Louis wouldn’t have called them beautiful. Each woman had long, dark hair covering her forehead and cheeks, enclosing a tiny T-shaped face.

Louis crouched behind the front seat while Vala stowed packages through the passenger’s door. Soon they were moving again.

An hour later, far from any habitation, Vala puffed off the road. Louis climbed down from his gunner’s perch. He was ravenous. Vala had bought food: a large smoked bird and nectar from the giant blossoms. Louis tore into the bird. Presently he asked, “You’re not eating?”

Vala smiled. “Not till night. But I will drink with you.” She took the colored glass bottle around to the back of the vehicle and ran clear fluid into the nectar. She drank, then passed the bottle. Louis drank.

Alcohol, of course. You couldn’t have oil wells on the Ringworld, could you? But you could build alcohol distilleries anywhere there were plants for fermenting. “Vala, don’t some of the, ah, subject races get to like this stuff too much?”

“Sometimes.”

“What do you do about it?”

The question surprised her. “They learn. Some become useless from drinking. They supervise each other if they must.”

It was the wirehead problem in miniature, with the same solution: time and natural selection. It didn’t seem to bother Vala… and Louis couldn’t afford to let it bother him. He asked, “How far is it to the city?”

“Three or four hours to the air road, but we would be stopped there. Louis, I have given thought to your problem. Why can’t you just fly up?”

“You tell me. I’m for it if nobody shoots at me. What do you think — would somebody shoot at a flying man, or would they let him talk?”

She sipped from the bottle of fuel and nectar. “The rules are strict. None but the City Builder species may come unless invited. But none have flown to the city either!”

She passed him the bottle. The nectar was sweet: like watered grenadine syrup, with a terrific kick from what must be 200 proof alcohol. He set it down and turned his goggles on the city.

It was vertical towers in a lily-pad-shaped clump, in a jarring variety of styles: blocks, needles tapered at top and bottom, translucent slabs, polyhedral cylinders, a slender cone moored tip down. Some buildings were all window; some were all balconies. Gracefully looping bridges or broad, straight ramps linked them at unpredictable levels. Granted that the builders weren’t quite human, Louis still couldn’t believe that anyone would build such a thing on purpose. It was grotesque.

“They must have come from thousands of miles around,” he said. “When the power stopped, there were buildings with independent power supplies. They all got together. Prill’s people mushed them all up into one city. That’s what happened, isn’t it?”

“Nobody knows. But, Louis, you speak as if you watched it happen!”

“You’ve lived with it all your life. You don’t see it the way I do.” He kept looking.

There was a bridge. From a low, windowless building at the top of a nearby hill, it rose in a graceful curve to touch the bottom of a huge fluted pillar. A poured stone road switchbacked uphill to the hilltop building.

“I take it the invited guests have to go through that place at the top, then up the floating bridge.”

“Of course.”

“What happens in there?”

“They are searched for forbidden objects. They are questioned. If the City Builders are choosy about whom they let up, why, so are we! Dissidents have sometimes tried to smuggle bombs up. Mercenaries hired by the City Builders once tried to send them parts to repair their magic water collectors.”

“What?”

Vala smiled. “Some still work. They collect water from the air. Not enough water. We pump water to the city from the river. If we argue over policy, they go thirsty, and we do without the information they gather, until a compromise is reached.”

“Information? What have they got, telescopes?”

“My father told me about it once. They have a room that shows what happens in the world, better than your goggles. After all, Louis, they have height and a view.”

“I should be asking your father all this. How—”

“That may not be a good idea. He is very… he does not see… ”

“I’m the wrong shape and color?”

“Yes, he would not believe you can make things like the things you own. He would take them.”

Tanj dammit. “What happens after they let the tourists through?”

“My father comes home with his left arm inscribed in a language only the City Builders know. The script gleams like silver wire. It does not wash off, but it fades in a falan or two.”

That sounded less like a tattoo than like printed circuitry. The City Builders might have more control over their guests than their guests knew. “Okay. What do the guests do up there?”

“They discuss policy. They make gifts: large quantities of food and some tools. The City Builders show them wonders and do rishathra with them.” Vala stood suddenly. “We should be moving.”

They had left the threat of bandits behind. Louis rode in front, beside Vala. Noise was as much a problem as the bumping; they had to raise their voices. Louis shouted, “Rishathra?”

“Not now, I’m driving.” Vala showed a wide expanse of teeth. “The City Builders are very good at rishathra. They can deal with almost any race. It helped them hold their ancient empire. We use rishathra for trading and for not having children until we want to mate and settle down, but the City Builders never give it up.”

“Do you know anyone who could get me invited up as a guest? Say, because of my machines.”

“Only my father. He wouldn’t.”

“Then I’ll have to fly up. Okay, what’s under the city? Can I just stroll underneath and float up?”

“Underneath is the shadow farm. You might pass for a farmer if you leave your tools behind. The farmers are of all races. It is a dirty job. The city sewer outlet is above, and sewage must be spread for the plants. The plants are all cave life, plants that grow in darkness.”

“But… Oh, sure, I see it now. The sun never moves, so it’s always dark under the city. Cave life, huh? Mushrooms?”

She was staring at him. “Louis, how can you expect the sun to move?”

“I forgot where I was.” He grimaced. “Sorry.”

“How can the sun move?”

“Well, of course it’s the planet that moves. Our worlds are spinning balls, right? If you live on one point, the sun seems to go up one side of the sky and down the other; then there’s night till it rises again. Why did you think the Ringworld engineers put up the shadow squares?”

The car began to weave. Vala was shaking, her face pale. Gently Louis asked, “Too much strangeness for you?”

“Not that.” She made an odd barking sound. Agonized laughter? “The shadow squares. Obvious to the stupidest of people. The shadow squares mock the day and night cycle for spherical worlds. Louis, I really hoped you were mad. Louis, what can we do?”

He had to give her some kind of answer. He said, “I thought of punching a hole under one of the Great Oceans, just before it reaches the point closest to the sun. Let several Earth-masses of water spew into space. The reaction would push the Ringworld back where it belongs. Hindmost, are you listening?”

The too-perfect contralto said, “It does not seem feasible.”

“Of course it’s not feasible. For one thing, how would we plug the hole afterward? For another, the Ringworld would wobble. A wobble that big would probably kill everything on the Ringworld, and lose the atmosphere too. But I’m trying. Vala, I’m trying.”

She made that odd barking sound and shook her head hard. “At least you do not think too small!”

“What would the Ringworld engineers have done? What if some enemy shot away most of the attitude jets? They wouldn’t have built the Ringworld without planning for something like this. I need to know more about them. Get me into the floating city, Vala!”

Chapter 18 — The Shadow Farm

They began to pass other vehicles: large or small windowed boxes, each with a smaller box at the rear. The road widened and became smoother. Now the fueling stations were more frequent and were of sturdy, square Machine People architecture. There were more and more boxy vehicles, and Vala had to slow. Louis felt conspicuous.

The road topped a rise, and the city was beyond. Vala played tour director as they drove downhill through growing traffic.

River’s Return had first seen life as a string of docks along the spinward shore of the broad brown Serpent River. That core region now had the look of a slum. The city had jumped the river via several bridges, and expanded into a circle with a piece bitten out of it. That missing piece was the shadow of the City Builders’ floating city.

Moving boxes surrounded them now. The air was scented with alcohol. Vala slowed to a crawl. Louis hunched low. Other drivers had ample opportunity to peer in at the strangely built man from the stars.

But they didn’t. They saw neither Louis nor each other; they seemed to see only other vehicles. And Vala drove on, into the center of town.

Here the houses crowded each other. Three and four stories tall, the houses were narrow, with no space between them. They pushed out above the street, cutting into the daylight. In marked contrast, public buildings were all low and sprawling and massive, situated on ample grounds. They competed for ground, not for height: never for height, with the floating city hovering over all.

Vala pointed out the merchants’ school, a wide complex of prosperous stone buildings. A block later she pointed down a cross-street. “My home is that way, in pink poured stone. See?”

“Any point in going there?”

She shook her head. “I thought hard on this. No. My father would never believe you. He thinks that even the City Builders’ claims are mostly boastful lies. I thought so too, once, but from what you tell me of this… Halrloprillalar… ”

Louis laughed. “She was a liar. But her people did rule the Ringworld.”

They left River’s Return and continued to port. Vala drove several miles farther before crossing the last of the bridges. On the far, portward side of the great shadow, she left an almost invisible side road and parked.

They stepped out into too-bright sunlight. They worked almost in silence. Louis used the flying belt to lift a fair-sized boulder. Valavirgillin dug a pit where it had been. Into the pit went most of Louis’s share of the fine black cloth. The dirt went back into the pit, and Louis lowered the boulder on it.

He put the flying belt into Vala’s backpack and shouldered it. The pack already held his impact suit, vest, binoculars, flashlight-laser, and the flask of nectar. It was lumpy and heavy. Louis set the pack down, adjusted the flying belt to give him some lift. He set the translator box just under the cover and shouldered the pack again.

He was wearing a pair of Vala’s shorts, with a length of rope to hold them up. They were too big for him. His depilated face would be taken as natural to his race. Nothing about him now suggested the star traveler, except the earplug for his translator. He’d risk that.

He could see almost nothing of where they were going. The day was too bright; the shadow, too extensive and too dark.

They walked from day into night.

Vala seemed to have no trouble picking her path. Louis followed her. His eyes adjusted, and he saw that there were narrow paths among the growths.

The fungi ranged from button-size to asymmetrical shapes as tall as Louis’s head, with stalks as thick as his waist. Some were mushroom-shaped, some had no shape at all. A hint of corruption was in the air. Gaps in the sprawl of buildings overhead let through vertical pillars of sunlight, so bright that they looked solid.

Frilly yellow fungus fringed in scarlet half smothered an outcropping of gray slate. Medieval lances stood upright, white tipped with blood. Orange and yellow and black fur covered a dead log.

The people were almost as various as the fungi. Here were Runners using a two-handed saw to cut down a great elliptical mushroom fringed in orange. There, small, broad-faced people with big hands were filling baskets with white buttons. Grass giants carried the big baskets away. Vala kept up a whispered commentary. “Most species prefer to hire themselves in groups, to protect against culture shock. We keep separate housing.”

There, a score of people were spreading manure and well-decayed garbage; Louis could smell it from a fair distance away. Were those of Vala’s species? Yes, they were Machine People, but two stood aside and watched, and they held guns. “Who are those? Prisoners?”

“Prisoners convicted of minor crimes. For twenty or fifty falans they serve society in this—” She stopped. One of the guards was coming to meet them.

He greeted Vala. “Lady, you should not be here. These shit-handlers may find you too good a hostage.”

Vala sounded exhausted. “My car died. I have to go to the school and tell them what happened. Please, may I cross the shadow farm? We were all killed. All killed by vampires. They have to know. Please.”

The guard hesitated. “Cross, then, but let me give you an escort.” He whistled a short snatch of music, then turned to Louis. “What of you?”

Vala answered for Louis. “I borrowed him to carry my pack.”

The guard spoke slowly and distinctly. “You. Go with the lady as far as she likes, but stay in the shadow farm. Then go back to what you were doing. What were you doing?”

Louis was mute without the translator. He thought of the flashlight-laser buried in his pack. Somewhat at random he laid his hand on a lavender-fringed shelf fungus, then pointed to a sledge stacked with similar fungi.

“All right.” The guard looked past Louis’s shoulder. “Ah.”

The smell told Louis before he turned. He waited, docile, while the guard instructed a pair of ghouls: “Take the lady and her porter to the far edge of the shadow farm. Guard them from harm.”

They walked single file along the paths, tending toward the center of the shadow farm. The male ghoul led, the female trailed. The smell of corruption grew riper. Sledges of fertilizer passed them on other paths.

Blood and tanj! How was he going to get rid of the ghouls?

Louis looked back. The ghoul woman grinned at him. She certainly didn’t mind the smell. Her teeth were big triangles, well designed for ripping, and her goblin ears were erect, alert. Like her mate, she wore a big purse on a shoulder strap, and nothing else; thick hair covered most of their bodies.

They reached a broad arc of cleared dirt. Beyond was a pit. Mist stood above the pit, hiding the far side. A pipe poured sewage into the pit. Louis’s eyes followed the pipe up, up into the black, textured sky.

The ghoul woman spoke in his ear, and Louis jumped. She was using the Machine People speech. “What would the king giant think if he knew that Louis and Wu were one?”

Louis stared.

“Are you mute without your little box? Never mind. We are at your service.”

The ghoul man was talking to Valavirgillin. She nodded. They moved off the path. Louis and the woman followed them around an extensive white shelf fungus, to huddle under its far lip.

Vala was edgy. The smell might be getting to her; it was certainly getting to Louis. “Kyeref says this is fresh sewage. In a falan it’ll be ripe and they’ll move the pipe and start hauling it away for fertilizer. Meanwhile nobody comes here.”

She took the pack off Louis’s back and spilled it out. Louis reached for the translator (the ghouls’ ears came sharply alert as his hand neared the flashlight-laser) and turned up the volume. He asked, “How much do the Night People know?”

“More than we ever thought.” Vala looked like she wanted to say more, but she didn’t.

The male answered. “The world is doomed to fiery destruction in not many falans. Only Louis Wu can save us.” He smiled, showed a daunting expanse of white wedge-shaped teeth. His breath was that of a basilisk.

“I can’t tell if you’re being sarcastic,” Louis said. “Do you believe me?”

“Strange events can spark an urge to prophecy in the insane. We know that you carry tools not known elsewhere. Your race is not known either. But the world is large, and we do not know all of it. Your furry friend’s race is stranger yet.”

“That’s not an answer.”

“Save us! We dare not interfere.” The ghoul lost a little of his grin, though his lips still didn’t meet. (That would take a conscious effort. Those big teeth… ) “Why should we care if you are insane? The activities of other species rarely interfere with our own lives. In the end they all belong to us.”

“I wonder if you aren’t the real rulers of the world.” Louis said that for diplomatic relations, then wondered uneasily if it might be true.

The woman answered. “Many species may claim to rule the world, or their own part of it. Would we lay claim to the forest tops of the Hanging People? Or to the airless heights of the Spill Mountain People? And what species would want our domain?” She was laughing at him, that was certain.

Louis said, “There’s a Repair Center for the world somewhere. Do you know where?”

“No doubt you are right,” the male said, “but we do not know where it might be.”

“What do you know about the rim wall? And the Great Oceans?”

“There are too many seas. I know not which you mean. There was activity along the rim wall before the great flames first appeared.”

“Was there! What kind of activity?”

“Many lifting devices raised equipment beyond even the level of the Spill Mountain People. There were City Builders and Spill Mountain People in great number, many other species in lesser number. They worked right at the upper edge of the world. Perhaps you can tell us the meaning of it all.”

Louis was dazed. “Tanj dammit. They must have been… ” Remounting the attitude jets, and he probably didn’t want to say so. So much power and ambition, so close, could be bad for a puppeteer’s nerves. “That’s a long way for carrion-eaters to pass messages.”

“Light travels farther than that. Does this news affect your predictions of doom?”

“I’m afraid not.” There might well be a repair crew in action somewhere, but they had almost run out of Bussard ramjets to be remounted. “But with the great flames acting, we should have more than the seven or eight falans I thought we had.”

“Good news. What will you do now?”

For a moment Louis was tempted to abandon the floating city and deal strictly with the ghouls. But he’d come too far, and after all, there were ghouls everywhere. “I’ll wait for night and then go up. Vala, your share of the cloth is in the vehicle. I’d be obliged if you don’t show it to anyone or tell anyone about me for… a couple of turns should do it. My share you can dig up in a falan if nobody comes for it. And I’ve got this.” He patted a vest pocket, where a square yard of superconductor was folded into the bulk of a handkerchief.

“I wish you wouldn’t take it to the city,” Vala said.

“After all, they’ll think its just cloth unless I tell them different,” Louis said. It was almost a lie. Louis intended to use the superconductor.

The ghouls stared when he took off his shorts — adding detail to his description, no doubt, to help them find his species’ home on the Ringworld. He donned impact armor.

The female suddenly asked, “How did you convince a Machine People woman that you were sane?”

Vala told her, while Louis donned vest and goggles and pocketed the flashlight-laser. The ghouls almost lost their smiles. The woman asked, “Can you save the world?”

“Don’t count on me. Try to find the Repair Center. Spread the word. Try questioning the bandersnatchi — the great white beasts who live in the great swamp to spinward.”

“We know of them.”

“Good. Vala—”

“I go now to tell how my companions died. We may not meet again, Louis.” Valavirgillin picked up the empty pack and walked quickly away.

“We should escort her,” the female ghoul said. They left.

They hadn’t said good luck. Why? The way they lived… they might all be fatalists. Luck would mean nothing to them.

Louis scanned the textured sky. He was tempted to go now, immediately. Better to wait for night. He spoke into the translator: “Hindmost, are you there?”

Apparently the puppeteer wasn’t.

Louis stretched out under the shelf fungus. The air seemed cleaner near the ground. He sipped meditatively at the fuel-and-nectar bottle Vala had left him.

What were the ghouls? Their position in the ecology seemed very secure. How had they kept their intelligence? Why would they need intelligence? Perhaps they had to fight for their prerogatives on occasion. Or for respect. Complying with a thousand local religions could also require considerable verbal facility.

More to the point: how could they help him? Was there a ghoulish enclave somewhere that remembered the source of the immortality drug? Which, by hypothesis, was made from Pak tree-of-life root…

One thing at a time. Try the city first.

The pillars of light thinned, then faded out. Other lights appeared in the solid sky: hundreds of lighted windows. None showed directly above him. Who would occupy a basement above a garbage dump? (Someone who couldn’t afford lighting?)

The shadow farm seemed deserted. Louis heard only the wind. Standing on the shelf fungus gave him a glimpse of distant windows flickering as if with firelight: housing for the farmers around the perimeter.

Louis touched the lift knob on his flying belt and went up.

Chapter 19 — The Floating City

At something over a thousand feet the smell of fresh air became more pronounced, and the floating city was around him. He circled the blunt tip of an inverted tower: four levels of dark windows, and a garage below that. The big garage door was closed and locked. Louis circled, looking for a broken window. There weren’t any.

These windows must have survived for eleven hundred years. Probably he couldn’t break one if he tried. He didn’t want to enter the city as a burglar anyway.

Instead, he let himself rise along the sewer pipe, hoping to gain privacy that way. There were ramps around him now, but no street lights anywhere. He guided himself to a walkway and settled on it. Now he felt less conspicuous.

There was nobody in sight. The broad ribbon of poured stone curved away among the buildings, left and right, up and down, putting out pseudopods at random. With a thousand feet of empty space below, there were no guardrails. Halrloprillalar’s people must be closer to their brachiating past than Earth’s people. Louis strolled toward the lights, keeping nervously to the center of the walk.

Where was everybody? The city had an insular look, Louis thought. There was housing in plenty, and ramps between the housing areas, but where were the shopping centers, the playhouses, the bars, the malls, parks, sidewalk cafés? Nothing advertised itself, and everything was behind walls.

Either he should find someone to introduce himself to, or he should be hiding. What about that glass slab with the dark windows? If he entered from above, he could make certain it was deserted.

Someone came down the walk toward him.

Louis called, “Can you understand me?” and heard his words translated into the Machine People tongue.

The stranger answered in the same language. “You should not walk about the city in darkness. You might fall.” He was closer now. His eyes were huge; he was not of the City Builder species. He carried a slender staff as long as himself. With the light behind him, Louis could see no more of him. “Show your arm,” he said.

Louis bared his left arm. Of course it bore no tattoos. He said what he had planned to say from the beginning. “I can repair your water condensers.”

The staff slashed at him.

It rapped his head glancingly as Louis threw himself backward. He rolled and was on his feet, crouching, trained reflexes working fine, with his arms coming up just too late to block the staff. It cracked against his skull. Lights flared behind his eyes and went out.

He was in free fall. Wind roared past him. Even to a man nearly unconscious, the connection was obvious. Louis thrashed in panic in the dark. Blowout in a spacecraft! Where am I? Where are the meteor patches? My pressure suit? The alarm switch?

Switch — He half remembered. His hands leaped to his chest, found flying-belt controls, twisted the lift knob hard over.

The belt lifted savagely and swung him around, feet down. Louis tried to shake the mists out of his head. He looked up. Through a gap in darkness he saw the solar corona glowing around a shadow square; he saw hard darkness descending to smash him. He twisted the lift knob to stop his rapid rise.

Safe.

His belly was churning and his head hurt. He needed time to think. Clearly his approach had been wrong. But if the guard had rolled him off the walk… Louis patted his pockets; everything was there. Why hadn’t the guard robbed him first?

Louis half remembered the answer: he’d jumped, missed the guard, rolled. And passed out in midair. That put a different face on the matter. It might even have been best to wait. Too late now.

So try the other approach.

He swam beneath the city, outward toward the rim. Not too far. There were too many lights along the perimeter. But near the center was a double cone with no lights showing at all. The lower tip was blunt: a carport with a poured-stone ledge protruding. Louis floated into the opening.

He raised the amplification of his goggles. It worried him that he hadn’t done that earlier. Had the blow to his head left him stupid?

Prill’s people, the City Builders, had had flying cars, he remembered. There was no car here. He found a rusted metal track along the floor, and a crude, armless chair at the far end, and bleachers: three rows of raised benches on either side of the track. The wood had aged, the metal was crumbly with rust.

He had to examine the chair before he understood. It was built to run down the track and to flop forward at the end. Louis had found an execution chamber, with provision for an audience.

Would he find courtrooms above? And a jail? Louis had about decided to try his luck elsewhere when a gravelly voice spoke out of the dark, in a speech he hadn’t heard in twenty-three years. “Intruder, show your arm. Move slowly.”

Again Louis said, “I can make your water condensers work,” and heard his translator speak in Halrloprillalar’s tongue. It must have been already in the translator, in storage.

The other stood in a doorway at the top of a flight of stairs. He was Louis’s height, and his eyes glowed. He carried a weapon like Valavirgillin’s. “Your arm is bare. How did you come here? You must have flown.”

“Yes.”

“Impressive. Is that a weapon?”

He must mean the flashlight-laser. “Yes. You see very well in the dark. What are you?”

“I am Mar Korssil, a female of the Night Hunters. Set down your weapon.”

“I won’t.”

“I am reluctant to kill you. Your claim might be true—”

“It is.”

“I am reluctant to wake my master, and I will not let you pass this door. Set down your weapon.”

“No. I’ve already been attacked once tonight. Can you lock that door so that neither of us can open it?”

Mar Korssil tossed something through the door; it jingled as it struck. She closed the door behind her. “Fly for me,” she said. Her voice was still a gravelly bass.

Louis lifted a few feet, then settled back.

“Impressive.” Mar Korssil came down the stairs with her weapon at ready. “We have time to talk. In the morning we will be found. What do you offer, and what do you want?”

“Was I right in guessing that your water condenser doesn’t work? Did it stop at the Fall of the Cities?”

“It has never worked to my knowledge. Who are you?”

“I am Louis Wu. Male. Call my species the Star People. I come from outside the world, from a star too dim to see. I have stuff to repair at least some of the water condensers in the city, and I have hidden much more. It may be that I can give you lighting too.”

Mar Korssil studied him with blue eyes as big as goggles. She had formidable claws on her fingers, and buck teeth like axheads. What was she, a rodent-hunting carnivore? She said, “If you can repair our machines, that is good. As to repairing those of other buildings, my master will decide. What do you want?”

“A great deal of knowledge. Access to whatever the city holds in the way of stored knowledge, maps, histories, tales—”

“You cannot expect us to send you to the Library. If your claim is true, you are too valuable. Our building is not wealthy, but we may buy knowledge from the Library if you have specific questions.”

It was becoming obvious: the floating city was no more a city than Pericles’ Greece had been a nation. The buildings were independent, and he was in the wrong building. “Which building is the library?” he asked.

“At the port-by-spinward perimeter, a cone moored tip down… Why do you ask?”

Louis touched his chest, rose, moved toward the outer night.

Mar Korssil fired. Louis fell sprawling. Flames blazed against his chest. He yelled and jerked the harness loose and rolled away. The flying-belt controls burned, a smoky yellow flame with blue-white flashes in it.

Louis found the flashlight-laser in his hand, pointed at Mar Korssil. The Night Hunter seemed not to notice. “Do not make me do that again,” she said. “Are you wounded?”

Those words saved her life; but Louis had to kill something. “Drop the weapon or I slice you in half,” he said, “like this.” He waved the laser beam through the execution chair; it flamed and fell apart.

Mar Korssil didn’t move.

“I only want to leave your building,” Louis said. “You’ve marooned me. I’ll have to enter your building, but I’ll leave by the first ramp I find. Drop the weapon or die.”

A woman’s voice spoke from the stairway. “Drop the gun, Mar Korssil.”

The Night Hunter did.

The woman came down the stairs. She was taller than Louis, and slender. Her nose was tiny, her lips invisibly thin. Her head was bald, but rich white hair flowed down her back from behind her cars and the back of her neck. Louis guessed that the white hair was a mark of age. She showed no fear of him. He asked, “Do you rule here?”

“I and my mate-of-record rule. I am Laliskareerlyar. Did you call yourself Luweewu?”

“Close enough.”

She smiled. “There is a peephole. Mar Korssil signaled from the garage: an unusual act. I came to watch and listen. I am sorry about your flying device. There are none left in all the city.”

“If I repair your water condenser, will you set me free? And I need advice.”

“Consider your bargaining position. Can you resist my guards who wait outside?”

Louis had almost resigned himself to killing his way out. He made one more try. The floor seemed to be the usual poured stone. He ran the laser beam in a slow circle, and a patch of stone a yard across dropped into the night. Laliskareerlyar lost her smile. “Perhaps you can. It shall be as you say. Mar Korssil, come with us. Stop anyone who tries to interfere. Leave your gun where it lies.”

They climbed a spiral escalator that no longer ran. Louis counted fourteen loops, fourteen stories. He wondered if he had been wrong about Laliskareerlyar’s age. The City Builder woman climbed briskly and had breath left over for conversation. But her hands and face were wrinkled as if worn too long.

An unsettling sight. Louis wasn’t used to that. Intellectually he knew what it was: the sign of age, and the sign of her ancestor, the Pak protector.

They climbed by the light of Louis’s flashlight-laser. People appeared at doorways; Mar Korssil warned them back. Most were City Builders, but there were other species too.

These servants had served the Lyar family for many generations, Laliskareerlyar explained. The Mar family of night watchmen had been policemen serving a Lyar judge. The Machine People cooks had served almost as long. Servants and City Builder masters saw themselves as one family, bound by periodic rishathra and old loyalties. All told, Lyar Building held a thousand people, half of them interrelated City Builders.

Louis stopped to look through a window halfway up. A window, in a stairwell that ran through the core of a building? It was a hologram, a view along one of the rim walls, showing a vast stretch of Ringworld landscape. One of the last of the Lyar treasures, Laliskareerlyar told him with pride and regret. Others had been sold over hundreds of falans to pay water fees.

Louis found himself talking too. He was wary and angry and tired, but there was something about the old City Builder woman that drew him out. She knew about planets. She didn’t question his veracity. She listened. She looked so much like Halrloprillalar that Louis found himself talking about her: about the ancient, immortal ship’s whore who had lived as a half-mad goddess until Louis Wu and his motley crew arrived; how she had helped them, how she had left her ruined civilization with them, how she had died.

Laliskareerlyar asked, “Is that why you didn’t kill Mar Korssil?”

The Night Hunter woman looked at him with great blue eyes.

Louis laughed. “Maybe.” He told them of his conquest of the sunflower patch. He was skirting a dangerous subject, for he saw no point in telling Laliskareerlyar that the world was going to brush against its sun. “I want to leave the world knowing that I’ve done no damage. I’ve got more of that cloth buried near here… Tanj! I can’t think of any way to reach it now.

They had reached the top of the spiral. Louis was huffing. Mar Korssil unlocked a door; there were more stairs beyond. Laliskareerlyar asked, “Are you nocturnal?”

“What? No.”

“We had best wait for day. Mar Korssil, go and send us breakfast. Send Whil, with tools. Then go to sleep.” As Mar Korssil trotted obediently downstairs, the old woman sat cross-legged on ancient carpet. “I expect we must work outside,” she said. “I don’t understand the risk you took. For what? Knowledge? What knowledge?”

It was difficult to lie to her, but the Hindmost might well be listening. “Do you know anything of a machine to change one kind of matter into another? Air into dirt, lead into gold?”

She was interested. “Ancient magicians were said to be able to turn glass into diamonds. But these were children’s tales.”

So much for that. “What of a Repair Center for the world? Are there legends about that? Telling its location?”

She stared. “As if the world were no more than a made thing, a larger version of the city?”

Louis laughed. “Much larger. Much much much larger. No?”

“No.”

“What about an immortality drug? I know that’s real. Halrloprillalar used it.”

“Of course it was real. There is none left in the city, nor anywhere else that I know of. The tale is a favorite with” — the translator used an Interworld phrase — “con men.”

“Does the tale tell where it might have come from?”

A young City Builder woman came puffing up the stairs carrying a shallow bowl. Louis’s fears of poison disappeared at once. The stuff was lukewarm, something like oatmeal, and they ate with their hands from the one bowl.

“The youth drug comes from spinward,” the old woman said, “but I know not how far to spinward. Is this the treasure of knowledge you came for?”

“Any of several treasures. That would be a good one.” There would certainly have been tree-of-life in the Repair Center, Louis thought. I wonder how they’d handle it? Surely no human being would want to be a protector? But there might be hominids who would… Well, those puzzles could wait.

Whil was a burly hominid with a simian face, dressed in a sheet whose original color was lost to time. It was a mad god’s rainbow now. Whil didn’t talk much. His arms were short and thick and looked very strong. He led them up the last flight of steps, carrying his toolbox, and out into the dawn.

They were on the lip of a funnel, at the truncated tip of the double cone. The rim was only a foot across. Louis’s breath caught in his throat. With his flying belt dead, he had reason to fear heights. Wind rushed past him, whipping Whil’s sheet into a fluttering multicolored flag.

Laliskareerlyar asked, “Well? Can you fix it?”

“Not from here. There must be machinery below.”

There was, but it wasn’t easy to reach. The crawl space was inches wider than Louis Wu. Whil crawled ahead of him, opening panels, as instructed.

The crawl space was doughnut-shaped, circling the machinery that must circle the funnel. And the water was supposed to precipitate on the funnel, no doubt. By refrigeration? Or had they something more sophisticated?

The widgetry concealed by the panels was tightly packed, and a total mystery to Louis Wu. It was sparkling clean, except for… yah. He peered closer, not breathing. A wire-thin worm trail of dust had fallen through the widgetry. Louis tried to guess where it had fallen from. He’d have to assume the rest of the machinery was still functional.

He backed out. From Whil he borrowed thick gloves and a pair of needle-nosed pliers. He cut a strip from the edge of the black cloth in his vest and twisted it. He strung it between two contacts and fastened them.

Nothing obvious happened. He continued around the circle, following Whil. In all he found six worm trails of dust. He fastened six twisted strips of superconductor where he thought they belonged.

He wriggled out of the crawl space. “Of course your power source could be long dead,” he said.

“We must see,” said the old woman. She went up the stairs to the roof. Louis and Whil followed.

The smooth face of the funnel seemed misted over. Louis knelt and reached to touch it. Wet. The water was warm. Already it was beading and flowing downslope to the pipes. Louis nodded thoughtfully. Another good deed that wouldn’t matter in fifteen falans.

Chapter 20 — Economics In Lyar

Just below the thick waist of Lyar Building was what seemed to be a combination audience chamber and bedroom. A huge circular bed with a curtained canopy, couches and chairs around small and large tables, a picture-window wall facing the nearer edge of the shadow farm, a bar built to offer a wide variety of potables. That variety was gone. Laliskareerlyar poured from a crystal decanter into a two-handled goblet, sipped, and passed it across to Louis.

He asked, “Do you hold audiences in here?”

She smiled. “Of a sort. Family gatherings.”

Orgies? Very likely, if rishathra was what held the Lyar family together. A family fallen on hard times. Louis sipped from the goblet, tasted nectar-and-fuel. The sharing of cups and food dishes — was fear of poison behind that? But she did it so naturally. And there were no diseases on the Ringworld.

“What you have done for us will increase our status and our funds,” said Laliskareerlyar. “Ask.”

“I need to reach the Library, enter it, and persuade the people who rule there to let me make free use of all their knowledge.”

“That would be very expensive.”

“Not impossible? Good.”

She smiled. “Too expensive. The relationship among the buildings is complicated. The Ten rule the tourist trade—”

“Ten what?”

“Ten large buildings, Luweewu, the most powerful among us. Nine still have lights and water condensers. Together they built the bridge to Sky Hill. Well, they rule the tourist trade, and they pay fees to the lesser buildings to cover hospitality for their alien guests, the use of all public places, and special fees for events in private buildings. They make all agreements with other species, as with the water the Machine People pump up to us. We pay fees to the Ten for water and for special concessions. Yours would be a very special concession although we pay the Library a general fee for education.

“The Library is one of the Ten?”

“Yes. Luweewu, we do not have the money. Is there a chance that you can do the Library a service? Perhaps your research would help them.”

“It’s possible.”

“They would return some of the fee for a service rendered. Even more than we gave, possibly. But we don’t have it. Would you sell them your light weapon or the machine that talks for you?”

“I think I’d better not.”

“Can you repair more water condensers?”

“Maybe. Did you say one of the Ten does not have a working water condenser? Then why are they one of the Ten?”

“Orlry Building has been among the Ten since the Fall of the Cities. Tradition.”

“What were they when the cities fell?”

“A military installation, a storehouse for weapons.” She ignored Louis’s chortling. “They have a fondness for weapons. Your light-projector—”

“I’d be afraid to let it go. But maybe they’d like their water condenser fixed.”

“I will learn what fee they ask to let you into Orlry Building.”

“You’re joking.”

“No. You must be guarded, to prevent your carrying away weapons. You pay an entertainment fee to see the ancient weapons, and more if they are to be demonstrated. If you see their maintenance facilities, you may learn weaknesses. I will ask.” She stood. “Shall we indulge in rishathra?”

Louis had been expecting that, a little, and it wasn’t Laliskareerlyar’s odd appearance that made him hesitate. It was the terror of taking off his armor and his tools. He remembered an old sketch of a king brooding on his throne. I’m paranoid. But am I paranoid enough?

But he was far overdue for sleep! He was simply going to have to trust the Lyars. “Good,” he said. He began to strip off his armor.

Age had treated Laliskareerlyar oddly. Louis knew ancient literature, plays and novels that predated boosterspice. Age was a crippling disease… but this woman wasn’t crippled. Her skin was loose on her, and her limbs didn’t bend as far as Louis’s. But she had an endless interest in love, and in the strangeness of Louis’s body and reflexes.

It was a long time before he slept. He had begged off telling her about the plastic under his hair. He wished she hadn’t reminded him of that. The Hindmost had a working droud… and he hated himself for wanting it.

He was awakened near nightfall. The bed jolted twice, and he blinked and rolled over. He faced Laliskareerlyar and a City Builder man who had also been touched by age.

Laliskareerlyar introduced him as Fortaralisplyar, her mate of record and Louis’s host. He thanked Louis for his work on the building’s old machinery. Dinner was already on one of the tables, and Louis was invited to share it with them: a large bowl of stew, too bland for Louis’s taste. He ate.

“Orlry Building asks more than we have,” Fortaralisplyar told Louis. “We have bought for you the right to enter three of our neighbors’ buildings. If you succeed in repairing even one of their water condensers, we can get you into Orlry Building. Is that satisfactory?”

“Excellent. I need machines that haven’t worked in eleven hundred years, and haven’t been tampered with either.”

“My mate told me.”

Louis left them to their sleep as dark was falling. They had invited him to join them, and the great bed was roomy enough, but Louis was slept out and restless.

The great building was like a tomb. From the upper floors Louis watched for activity in the maze of bridges. He saw nothing but an occasional big-eyed Night Hunter. It figured. If the City Builders slept ten hours out of thirty, it might as well be during the dark. He wondered if they were an asleep in the lighted buildings too.

“Calling the Hindmost,” he said.

“Yes, Louis. Must we translate?”

“No need, we’re alone. I’m in the floating city. It’ll take me a day or two to get into the Library. I think I’m marooned here. My flying belt’s ruined.”

“Chmeee still will not answer.”

Louis sighed. “What else is new?”

“In two days my first probe will complete its circuit of the rim wall. I can bring it to the floating city. Will you want me to negotiate directly with the inhabitants? We are good at that. At least I can lend credence to your tale.”

“I’ll let you know. What about the Ringworld attitude jets? Have you found any more mounted?”

“No. Of those you know of, all twenty-one are firing. Can you see them?”

“Not from here. Hindmost? Can you learn anything about the physical properties of scrith, Ringworld floor material? Strength, flexibility, magnetic properties?”

“I have been working on that. The rim wall is available to my instruments. Scrith is very much denser than lead. The scrith floor of the Ringworld is probably less than a hundred feet thick. I’ll show you my data when you return.”

“Good.”

“Louis, I can give you transportation, if need be. It would be easier if I could send Chmeee.”

“Great! What kind of transportation?”

“You will have to wait for my probe. I will give further instructions then.”

He watched the nearly empty city for a while after the Hindmost hung up. He felt depressed. Alone in a gone-to-seed building in a gone-to-seed city, without his droud…

A voice behind his shoulder said, “You told my mistress that you are not nocturnal.”

“Hello, Mar Korssil. We use electric lighting. Some of us keep strange hours. Anyway, I’m used to a shorter day.” Louis turned around.

The big-eyed humanoid wasn’t pointing her weapon at Louis, exactly. She said, “These past falans, the day has been changing its length. It is distressing.”

“Yah.”

“Whom did you speak to?”

“A two-headed monster.”

Mar Korssil departed. Perhaps she was offended. Louis Wu remained at the window, free-associating through the memories of a long and eventful life. He had given up hope of returning to known space. He’d given up the droud. Perhaps it was time to give up… more.

Chkar Building was a poured-stone slab covered in balconies. Explosions had scarred one side of the building, exposing the metal skeleton in places. The water condenser was a trough along the top, slightly canted. An old explosion had sprayed metal droplets into the machinery below. Louis didn’t expect his repairs to work, and they didn’t.

“Mine is the blame,” Laliskareerlyar said. “I had forgotten that Chkar Building fought with Orlry Building two thousand falans ago.”

Panth Building was built like an onion standing on its tip. Louis guessed that the building had started life as a health club; he recognized pools, spas, hotboxes, massage tables, a gymnasium. The place seemed to have plenty of water. And a faint half-familiar smell tickled at his memory…

Panth had also fought with Orlry. There were craters. A bald young man named Arrivercompanth swore that the water condenser had never been damaged. Louis found the dust tracks in the machinery, and the contacts above them. When he had made his repairs, there were water droplets forming on the rounded roof and running into a gutter.

There was some difficulty about payment. Arrivercompanth and his people wanted to offer rishathra and promises. (And then Louis recognized the scent tickling his nose and hindbrain. He was in a house of ill repute, and there were vampires somewhere about.) Laliskareerlyar wanted cash now. Louis tried to follow her argument. He gathered that the Ten would be unhappy when Panth stopped buying water, and only too happy to levy a fine against them for fraud. Arrivercompanth paid.

Gisk had been a condominium, or something similar, at the Fall of the Cities. It was a cube with an air well down the center, and it was half empty. Judging by the smell of the place, Gisk had been restricting its use of water overmuch. Louis was learning the look of water-condensation machinery. He made his repairs quickly, and they worked. The Gisks paid at once. They fell at Laliskareerlyar’s feet to express their thanks… ignoring her tool-wielding servant. Oh, well.

Fortaralisplyar was delighted. He packed a double-handful of metal coins into Louis’s vest and explained the tricky etiquette of bribery. The face-saving language would strain his translator to the limits. “When in doubt, don’t,” Fortaralisplyar told him. “I will come with you to Orlry Building tomorrow. Let me do the bargaining.”

Orlry Building was on the port side of the city. Louis and Fortaralisplyar took their time, sightseeing, walking the highest ramps to get a better view. Fortaralisplyar was proud of his city. “A bit of civilization remained even after the Fall,” he said. He pointed out Rylo, a building that had been an emperor’s castle. It was beautiful but scarred. The emperor had tried to claim the city for his own at about the time Orlry Building arrived. A fluted column shaped like a Greek pillar, supporting nothing but itself, was Chank, which had been a shopping center. Without the supplies aboard Chank — from markets, restaurants, clothing and bedding stores, even toy shops — for trading with the Machine People, the city would have died early. From the basement of Chank the air road spiraled down to Sky Hill.

Orlry Building was a disc forty feet thick and ten times that wide, built along the lines of a pie. The massive tower at one edge, elaborated with gun emplacements and railed platforms and a derrick, reminded Louis of the bridge of a great ship — a battleship. The walkway to Orlry was broad, but there was only one walkway and one entrance. Along the upper rim were hundreds of small projections. Louis guessed that they were cameras or other sensors, and that they no longer worked. Windows had been chopped into Orlry’s sides after the building was raised. The glass in them fitted poorly.

Fortaralisplyar was dressed in yellow and scarlet robes of what appeared to be vegetable fiber: coarse by Louis’s standards, but grand from a distance. Louis followed him into Orlry, into a large reception area. There was light, but it flickered: scores of alcohol lamps burning near the ceiling.

Eleven City Builder types of both sexes waited for them. They were dressed almost identically, in loose pants with tight cuffs and brightly colored capes. The edges of the capes were cut elaborately and without symmetry. Badges of rank? The white-haired man who came smiling to greet them wore the most elaborately cut cape and a shoulder gun.

He spoke to Fortaralisplyar. “I had to see him for myself, this being who can give us water from machinery five thousand falans dead.”

The handgun in his worn plastic shoulder holster was small, with clean, efficient lines; but even a gun couldn’t make Filistranorlry look warlike. His small features showed happy curiosity as he examined Louis Wu. “He seems unusual enough, but… well. You have paid. We shall see.” He gestured to the soldiers.

They searched Fortaralisplyar, then Louis. They found his flashlight, tested it, gave it back. They puzzled over his translator until Louis said, “That speaks for me.”

Filistranorlry jumped. “So it does! Will you sell that?” He was speaking to Fortaralisplyar, who answered, “It is not mine.”

Louis said, “I would be mute without it.” Orlry’s master seemed to accept this.

The water condenser was a dip in the center of Orlry’s broad roof. The access tubes below were too small for Louis. Even if he took off his armor he wouldn’t fit, and he didn’t intend to do that. “What do you use for repairmen? Mice?”

“Hanging People,” Filistranorlry said. “We must rent their services. Chilb Building was to have sent them by now. Do you see any other problems?”

“Yes.” By now the machinery was familiar enough; Louis had repaired three buildings and failed at a fourth. He could see what ought to be a pair of contacts. He looked for the dust below them, and it wasn’t there. “Were there earlier attempts at repair?”

“I assume so. How would we know, after five thousand falans?”

“We’ll wait for the repairmen. I hope they can follow orders.” Tanj! Somebody long dead had neatened things up by blowing the telltale dust tracks away. But Louis was sure he could get his arms in there…

Filistranorlry asked, “Would you care to see our museum? You’ve bought that right.”

Louis had never been a weapons buff. He recognized some of the principles, if not the forms, behind the killing tools in the glass cases and behind the glass walls. Most of them used projectiles or explosions or both. Some would throw strings of tiny bullets that exploded like small firecrackers in enemy flesh. The few lasers were massive and cumbersome. Once they must have been mounted on tractors or floating platforms, but those had been scavenged for use elsewhere.

A City Builder arrived with half a dozen workmen. The Hanging People stood as high as Louis’s floating ribs. Their heads seemed too large for their bodies; their toes were long and dexterous, and their fingers nearly brushed the floor. “This is probably a waste of time,” one said.

“Do it right and you’ll be paid anyway,” Louis told him. The little man sneered.

They wore armless gowns covered in pockets, the pockets heavy with tools. When the soldiers wanted to search them, they stripped off the gowns and let the soldiers search those. Perhaps they didn’t like to be touched.

So small. Louis whispered to Fortaralisplyar, “Does your species do rishathra with those?”

The City Builder chuckled. “Yes, but carefully.”

The Hanging People clustered around Louis Wu’s shoulders, peering, as he reached into the access tube. He wore the insulated gloves he’d borrowed from Mar Korssil. “These are what the contacts look like. Fasten the cloth strip thus… and thus. You should find six pairs of contacts. There may be a worm track of dust below.”

After they had disappeared around the curve of the access tube, he told the masters of Orlry and Lyar, “We’ll never know it if they make a mistake. I wish we could inspect their work.” But he did not mention his other fear.

The Hanging People presently emerged. They all trooped up onto the roof: workers, soldiers, masters, and Louis Wu. There they watched as mist formed and condensed and water ran toward the center of the dip.

And six Hanging People now knew how to repair water condensers with strips of black cloth.

“I want to buy that black cloth,” Filistranorlry said.

The Hanging People and their City Builder master were already disappearing down the stairwell. Filistranorlry and ten soldiers blocked Louis and Fortaralisplyar from that escape route.

“I don’t intend to sell,” Louis said.

The silver-haired soldier said, “I hope to keep you here until I can persuade you to sell. If pressed, I will insist that you sell the talking box too.”

Louis had half expected this. “Fortaralisplyar, would Orlry Building keep you here by force?”

Lyar’s master looked Orlry’s master in the eye as he said, “No, Louis. The complications would be unpleasant. The lesser buildings would join to free me. The Ten would become the Nine rather than face a boycott on guests.”

Filistranorlry laughed. “The lesser buildings would grow thirsty… ” and his smile vanished as Fortaralisplyar’s grew. Lyar Building now had water to give away.

“You could not hold me. Guests would be pushed from the ramps. The dramas in Chkar and the facilities in Panth would be closed to you—”

“Go, then.”

“I take Louis.”

“You do not.”

Louis said, “Take the money and go. It’ll make things easier for all concerned.” His hand was in his pocket, on the flashlight-laser.

Filistranorlry held out a small bag. Fortaralisplyar took it, counted the contents. He walked through the soldiers and descended the stairway. When he was out of sight, Louis pulled the hood of the impact suit over his head.

“I offer a high price. Twelve -- “ something untranslated. “You would not be cheated,” Filistranorlry was saying. But Louis backed toward the edge of the roof. He saw Filistranorlry signal to the soldiers, and he ran.

The edge of the roof was a chest-high fence: zigzag iron spokes, carved to resemble elbow root. The shadow farm was far below. Louis ran along the fence toward the walkway. The soldiers were close, but Filistranorlry was standing back and firing his pistol. The roar was disconcerting, even terrifying. A slug slammed into Louis’s ankle; the suit went rigid, and he rolled like a tumbled statue, picked himself up, and ran again. As two soldiers threw themselves at him, he swung over the fence and dropped.

Fortaralisplyar was on the walkway. He turned, startled.

Louis landed flat on his face, in an impact suit gone rigid as steel. The form-fitting coffin supported him, but he was still stunned. Hands helped him to his feet before he really wanted to get up. Fortaralisplyar put his shoulder under Louis’s armpit and began walking them away.

“Get away. They might shoot,” Louis gasped.

“They would not dare. Are you hurt? Your nose is bleeding.”

“It was worth it.”

Chapter 21 — The Library

They entered the Library via a small vestibule in the bottom of the cone, the tip.

Behind a wide, massive desk, two librarians worked at reading screens: bulky machines, styled like a cluster of boxes, that used book tapes rolling through a reader. The librarians looked like a priest and priestess in identical blue robes with jaggedly cut collars. It was some minutes before the woman looked up.

Her hair was pure, clean white. Perhaps she’d been born with white hair, because she wasn’t old. A woman of Earth would have been about to take her first shot of boosterspice. She was straight and slender, and pretty, Louis thought. Flat-chested, of course, but nicely built. Halrloprillalar had taught Louis to find a bald head and a well-shaped skull sexy. If she would smile… but even to Fortaralisplyar she was rude and imperious. “Yes?”

“I am Fortaralisplyar. Have you my contract?”

She tapped at the keyboard of the reading machine. “Yes. Is this the one?”

“He is.”

Now she looked at Louis. “Luweewu, can you understand me?”

“I can, with the aid of this.”

When the translator spoke, her calm cracked, but only for a moment. She said, “I am Harkabeeparolyn. Your master has purchased your right to unlimited research for three days, with an option to purchase an additional three days. You may roam the Library at will, barring the residential sections, the doors marked in gold. You may use any machine unless it is marked thus.” She showed him: an orange tic-tac-toe grid. “To use these, you need help. Come to me or to anyone whose collar is cut like mine. You may use the dining room. For sleep or a bath you must return to Lyar Building.”

“Good.”

The librarian looked puzzled. Louis was a little startled himself. Why had he said that with such force? It struck him that Lyar Building felt more like home to him than the apartment on Canyon ever had.

Fortaralisplyar paid out silver coins, bowed to Louis, and departed. The librarian turned back to her reading screen. (Harkabeeparolyn. He was tired of six-syllable names, but he’d better memorize it.) Harkabeeparolyn glanced around when Louis said, “There’s a place I’d like to find.”

“In the Library?”

“I hope so. I saw a place like it long ago. You stood at the center of a circle, and the circle was the world. The screen at the center turned, and you could make any part of the world show big—”

“We have a map room. Climb the stairs all the way up.” She turned away.

A tight spiral of metal stairs wound up the Library’s axis. Anchored only at the top and bottom, it was springy under his weight as he climbed. He passed doors marked in gold, all closed. Higher up, arched openings led to banks of reading screens with chairs. Louis counted forty-six City Builders using reading screens, and two elderly Machine People, and a compact, very hairy male you-name-it, and a ghoul woman all alone in one room.

The top floor was the map room. He knew when he had reached it.

They had found the first map room in an abandoned floating palace. Its wall was a ring of blue mottled with white. There had been globes of ten oxygen-atmosphere worlds, and a screen that would show a magnified view. But the scenes it showed were thousands of years old. They showed a bustling Ringworld civilization: glowing cities; craft zipping through rectangular loops along the rim wall; aircraft as big as this library: spacecraft much bigger.

They had not been looking for a Repair Center then. They’d been looking for a way off the Ringworld. Clearly the old tapes had been almost useless.

They’d been in too much of a hurry. So: twenty-three years later, in another kind of desperation, we try again…

Louis Wu emerged from the stairwell with the Ringworld glowing around him. Where the sun would have been, there was Louis Wu’s head. The map was two feet tall and almost four hundred feet in diameter. The shadow squares were the same height, but much closer in, hovering over a thousand square feet of jet black floor flecked with thousands of stars. The ceiling, too, was black spattered with stars.

Louis walked toward one of the shadow squares, and through it. Holograms, right, as with that earlier map room. But this time there were no globes of Earthlike worlds.

He turned to inspect the back of a shadow square. No detail showed: nothing but a dead-black rectangle, slightly curved.

The magnification screen was in use.

A three-foot-by-two-foot rectangular screen, with controls below, was mounted on a circular track that ran between the shadow squares and the Ringworld. The boy had an expanded view of one of the mounted Bussard ramjets. It showed as a glare of bluish light. The boy was trying to squint past it.

He must have just reached adolescence. Very fine brown hair covered his entire scalp, thickening at the back. He wore a librarian’s blue robes. His collar was wide and square, almost a cape, with a single notch cut into it.

Louis asked, “May I look over your shoulder?”

The boy turned. His features were small and nearly unreadable, as with any City Builder. It made him look older. “Are you allowed such knowledge?”

“Lyar Building has purchased full privileges for me.”

“Oh.” The boy turned back. “We can’t see anything anyway. In two days they’ll turn off the flames.”

“What are you watching?”

“The repair crew.”

Louis squinted into the glare. A storm of blue-white light filled the screen, with darkness at its core. The attitude jet was a dim pinkish dot at the center of the darkness.

Electromagnetic lines of force gathered the hot hydrogen of the solar wind, guided and compressed it to fusion temperatures, and fired it back at the sun. Machinery strove with single-minded futility to hold the Ringworld against the gravity of its star. But this was all that showed: blue-white light and a pinkish dot on the line of the rim wall.

“They’re almost finished,” the boy said. “We thought they’d call us for help, but they never came.” He sounded wistful.

“Maybe you don’t have the tools to hear them calling.” Louis tried to keep his voice calm. Repair crew! “They must be finished anyway. There aren’t any more motors.”

“No. Look.” The boy set the view zipping along the rim wall. The view stopped, jarringly, well beyond the blue glare. Louis saw bits of metal falling along the rim wall.

He studied them until he was certain. Bars of metal, a great spool-shaped cylinder — those were the dismantled components of what he had seen through Needle’s telescope. That was the scaffolding for remounting the Ringworld’s attitude jets.

The repair crew must have decelerated this equipment to solar orbital speed by using a segment of the rim transport system. But how did they plan to reverse the procedure? The machinery would have to be accelerated to Ringworld rotational speed at its destination.

By friction with the atmosphere? Those materials could be as durable as scrith. If so, heating would not be a problem.

“And here.” The view skidded again, spinward along the rim wall to the spaceport ledge. The four great City Builder ships showed clear. Hot Needle of Inquiry was a speck. Louis would have missed it if he hadn’t known just where to look: a mile from the only ship that still sported a Bussard ramjet around its waist.

“There, you see?” The boy pointed to the pair of copper-colored toroids. “There’s only one motor left. When the repair crew mounts that, they’ll be finished.”

Megatons of construction equipment were falling down the rim wall, no doubt accompanied by hordes of construction men of unknown species, all aimed at Needle’s parking space. The Hindmost would not be pleased.

“Finished, yes,” Louis said. “It won’t be enough.”

“Enough for what?”

“Never mind. How long have they been working, this repair team? Where did they come from?”

“Nobody wants to tell me anything,” the boy said. “Flup. Odorous flup. What’s everybody so excited about? Why am I asking you? You don’t know either.”

Louis let that pass. “Who are they? How did they find out about the danger?”

“Nobody knows. We didn’t know anything about them till they started putting up the machines.”

“How long ago?”

“Eight falans.”

Fast work, Louis thought. Just over a year and a half, plus whatever time it took them to get ready. Who were they? Intelligent, quick, decisive, not overwhelmed by large projects and large numbers — they might almost be… but the protectors were long gone. They had to be.

“Have they done other repairs?”

“Teacher Wilp thinks they’ve been unblocking the spillpipes. We’ve seen fog around some of the spill mountains. Wouldn’t that be a big thing, unblocking a spillpipe?”

Louis thought about it. “Big, all right. If you could get the sea-bottom dredges going again… you’d still have to heat the pipes. They run under the world. The sea-bottom ooze in a blocked pipe would freeze, I think.”

“Flup,” said the boy.

“What?”

“The brown stuff that comes out of a spillpipe is called flup.”

“Oh.”

“Where are you from?”

Louis grinned. “I came from the stars, in this.” He reached past the boy’s shoulder to point out the speck that was Hot Needle of Inquiry. The boy’s eyes grew big.

More clumsily than the boy had, Louis ran the view along the path the lander had taken since leaving the rim wall. He found a continent-sized expanse of white cloud where the sunflower patch had been. Farther to port was a wide green swamp, then a river that had cut itself a new bed, leaving the old as a twisting brown track through the yellow-brown desert. He followed the dry riverbed. He showed the boy the city of vampires; the boy nodded.

The boy wanted to believe. Men from the stars, come to help us! Yet he was afraid to look gullible. Louis grinned at him and continued.

The land turned green again. The Machine People road was easy to follow; in most places the land was clearly different to either side. Here the river curved back to join its old bed. He ran the scale up again and was looking down on the floating city. “Us,” he said.

“I’ve seen that. Tell me about the vampires.”

Louis hesitated. But after all, the boy’s species were this world’s experts at interspecies sex. “They can make you want to do rishathra with them. When you do, you get bitten on the neck.” He showed the boy the healed wound in his throat. “Chmeee killed the vampire that, uh, attacked me.”

“Why didn’t the vampires get him?”

“Chmeee’s like nothing in the world. He’s as likely to be seduced by a sausage plant.”

“We make perfume from vampires,” the boy said.

“What?” Something wrong with the translator?

The boy smiled too wisely. “One day you’ll see. I’ve got to go. Will you be here later?”

Louis nodded.

“What’s your name? Mine’s Kawaresksenjajok.”

“Luweewu.”

The boy left by the stairwell. Louis stood frowning at the screen.

Perfume? The smell of vampires in Panth Building… and now Louis remembered the night Halrloprillalar came to his bed, twenty-three years ago. She’d been trying to control him. She’d said so. Had she used vampire scent on him?

It couldn’t matter now. “Calling the Hindmost,” he said. “Calling the Hindmost.”

Nothing.

The screen wasn’t built to swivel. It faced always outward, away from the shadow squares. Annoying but informative: it could mean that the pictures were being beamed from the shadow squares themselves.

He reduced the scale on the screen. He sent the viewpoint swooping to spinward at impossible speed until he was looking down on a world of water. He dropped like an angel in a death dive. This was fun. The Library’s facilities were considerably better than Needle’s telescope.

The Map of Earth was old. Half a million years had distorted the continents. Or more? A million? Two? A geologist would have known.

Louis shifted to starboard of antispinward until the Map of Kzin filled the screen: islands clustered around a plate of glare ice. And how old was this Map’s togography? Chmeee might know.

Louis expanded the view. He hummed as he worked. He skimmed above yellow-and-orange jungle. His view crossed a broad silver band of river, and he followed it toward the sea. At the junctures of rivers there ought to be cities.

He almost skimmed past it. A delta where two rivers joined; a pale grid pattern imposed on jungle colors. Some human cities had “green belts,” but in this kzinti city they must cover more territory than the buildings. At maximum magnification Louis could just make out patterns of streets.

The kzinti had never liked big cities. Their sense of smell was too acute. This city was almost as big as the Patriarch’s seat of government on Kzin.

They had cities. What else? If they had any kind of industry, they’d need… seaports? Mining towns? Keep skimming.

Here the jungle was scrawny. The yellow-brown of barren soil showed through in a pattern that wasn’t city-shaped at all. It looked like a melted archery target. At a guess, it was a very large and very old strip mine.

Half a million years ago, or more, a sampling of kzinti had been dropped here. Louis didn’t expect to find mining towns. They’d be lucky to have anything left to mine. For half a million years they had been confined to one world, a world whose surface ended a few hundred feet down. But it seemed the kzinti had kept their civilization.

They had brains, these near-cats. They had ruled a respectable interstellar civilization. Tanj, it was kzinti who had taught humans to use gravity generators! And Chmeee must have reached the Map of Kzin hours ago, in his search for allies against the Hindmost.

Louis had followed the river to the sea. Now he skimmed his god’s-eye view “south” along the shoreline of the Map’s largest continent. He expected ports, though the kzinti didn’t use ships much. They didn’t like the sea. Their seaports were industrial cities; nobody lived there for pleasure.

But that was in the Kzinti Empire, where gravity generators had been used for millennia. Louis found himself looking down on a seaport that would have rivalled New York harbor. It crawled with the wakes of ships barely large enough to see. The harbor had the nearly circular look of a meteor crater.

Louis lowered the magnification, backing his viewpoint into the sky, to get an overview.

He blinked. Had his miserable sense of scale betrayed him again? Or had he mishandled the controls?

There was a ship moored across the harbor. It made the harbor look bathtub-sized.

The wakes of tinier ships were still there. It was real, then. He was looking at a ship as big as a town. It nearly closed off the arc of the natural harbor.

They wouldn’t move it often, Louis thought. The motors would chew up the sea bed something fierce. With the ship gone, the harbor’s wave patterns would change. And how would the kzinti fuel something so big? How had they fueled it the first time? Where did they find the metals?

Why?

Louis had never seriously wondered if Chmeee would find what he sought on the Map of Kzin. Not until now.

He spun the magnification dial. His viewpoint receded into space until the Map of Kzin was a cluster of specks on a vast blue sea. Other Maps showed near the edges of the screen.

The nearest Map to the Map of Kzin was a round pink dot. Mars… and it was as far from Kzin as the Moon was from Earth.

How could such distances be conquered? Even a telescope wouldn’t penetrate more than two hundred thousand miles of atmosphere. The idea of crossing that distance in a seagoing ship — even a ship the size of a small city — tanj!

“Calling the Hindmost. Louis Wu calling the Hindmost.” Time was running out for Louis Wu as repairmen moved in on Needle and Chmeee culled the Map of Kzin for warriors. Louis didn’t intend to mention any of this to the Hindmost. It would only upset the puppeteer.

What was the Hindmost doing that he couldn’t answer a call?

Could a human even guess at the answer?

Continue the survey, then.

Louis ran the scale down until he could see both rim walls. He looked for Fist-of-God Mountain near the Ringworld’s median line, to port of the Great Ocean. Not there. He expanded the scale. A patch of desert bigger than the Earth was still small against the Ringworld, but there it was, reddish and barren, and the pale dot near the center was… Fist-of-God, a thousand miles tall, capped with naked scrith.

He skimmed to port, tracing the path they had taken following Liar’s crash. Long before he was ready, he had reached water, a wide-flung arm of the Great Ocean. They had stopped within sight of that bay. Louis drifted back, looking for what would be an oblong of permanent cloud, seen from above.

But the eye storm wasn’t there.

“Calling the Hindmost! In the names of Kdapt and Finagle and Allah I summon thee, God tanj it! Calling—”

“I am here, Louis.”

“Okay! I’m in a library in the floating city. They’ve got a map room. Look up Nessus’s records of the map room we—”

“I remember,” the puppeteer said coolly.

“Well, that map room showed old tapes. This one is running on present time!”

“Are you safe?”

“Safe? Oh, safe enough. I’ve been using superconductor cloth to make friends and influence people. But I’m trapped here. Even if I could bribe my way out of the city, I’d still have to get past the Machine People station on Sky Hill. I’d rather not shoot my way out.”

“Wise.”

“What’s new at your end?”

“Two data. First, I have holograms of both of the other spaceports. All of the eleven ships have been rifled.”

“The Bussard ramjets gone? All of them?”

“Yes, all.”

“What else?”

“You cannot expect rescue from Chmeee. The lander has set down on the Map of Kzin in the Great Ocean,” the puppeteer reported. “I should have guessed. The kzin has defected, taking the lander with him!”

Louis cursed silently. He should have recognized that cool, emotionless tone. The puppeteer was badly upset; he was losing control of the finer nuances of human speech. “Where is he? What’s he doing?”

“I watched through the lander’s cameras as he circled the Map of Kzin. He found a capacious seagoing ship—”

“I found it too.”

“Your conclusions?”

“They tried to explore or colonize the other Maps.”

“Yes. In known space the kzinti eventually conquered other stellar systems. On the Map of Kzin they must have looked across the ocean. They were not likely to develop space travel, of course.”

“No.” The first step in learning space travel is to put something in orbit. On Kzin, low orbital velocity was around six miles per second. On the Map of Kzin, the equivalent was seven hundred and seventy miles per second. “They couldn’t have built too many of these ships either. Where would they get the metals? And the voyages would take decades, at least. I wonder how they even knew there were other Maps.”

“We may guess that they launched telescopic camera equipment aboard rockets. The instruments would have to perform quickly. A missile could not go into orbit. It would rise and fall back.”

“I wonder if they reached the Map of Earth? It’s another hundred thousand miles past Mars… and Mars wouldn’t make a good staging area.” What would kzinti have found on the Map of Earth? Homo habilis alone, or Pak protectors too? “There’s the Map of Down to starboard, and I don’t know the world to antispinward.”

“We know it. The natives are communal intelligences. We expect that they will never develop space travel. Their ships would need to support an entire hive.”

“Hospitable?”

“No, they would have fought the kzinti. And the kzinti have clearly given up the conquest of the Great Ocean. They seem to be using the great ship to block off a harbor.”

“Yah. I’d guess it’s a seat of government too. You were telling me about Chmeee.”

“After learning what he could by circling above the Map of Kzin, he hovered above the great ship. Aircraft rose and attacked him with explosive missiles. Chmeee allowed this, and the missiles did no harm. Then Chmeee destroyed four aircraft. The rest continued the attack until weapons and fuel were exhausted. When they returned to the ship, Chmeee followed them down. The lander presently rests on a landing platform on the great ship’s conning tower. The attack continues. Louis, is he seeking allies against me?”

“If it’s any comfort to you, he won’t find anything that can go up against a General Products hull. They can’t even hurt the lander.”

Long pause; then “Perhaps you’re right. The aircraft use hydrogen-burning jets and missiles propelled by chemical explosives. In any case, I must rescue you myself. You must expect the probe at dusk.”

“Then what? There’s still the rim wall. You told me stepping discs won’t send through scrith.”

“I used the second probe to place a pair of stepping discs on the rim wall as a relay.”

“If you say so. I’m in a building shaped like a top, at the port-by-spinward perimeter. Set the probe to hover until we decide what to do with it. I’m not sure I want to leave yet.”

“You must.”

“But all the answers we need could be right here in the Library!”

“Have you made any progress?”

“Bits and pieces. Everything Halrloprillalar’s people knew is somewhere in this building. I want to question the ghouls too. They’re scavengers, and they seem to be everywhere.”

“You only learn to ask more questions. Very well, Louis. You have several hours. I will bring the lander to you at dusk.”

Chapter 22 — Grand Theft

The cafeteria was halfway down the building. Louis gave thanks for a bit of luck: the City Builders were omnivores. The meat-and-mushroom stew could have used salt, but it filled the vacuum in his belly.

Nobody used enough salt. And all the seas were fresh water, except for the Great Oceans. He might be the only hominid on the Ringworld who needed salt, and he couldn’t live without it forever.

He ate quickly. Time pressed on the back of his neck. The puppeteer was already skittish. Surprising that he hadn’t already fled, leaving Louis and the renegade Chmeee and the Ringworld to their similar fates. Louis could almost admire the puppeteer for waiting to rescue his press-ganged crewman.

But the puppeteer might change his mind when he saw the repair crew coming at him. Louis intended to be back aboard Needle before the Hindmost turned his telescope in that direction.

He went back to the upper rooms.

The reading screens he tried all gave unreadable script and no pictures and no voice. Finally, at one of a bank of screens, his eye caught a familiar collar.

“Harkabeeparolyn?”

The librarian turned. Small flat nose; lips like a slash; bald scalp and a fine, delicate skull; long, wavy white hair… and a nice flare to her hips, and fine legs. In human terms she’d have been about forty. City Builders might age more slowly than human beings, or faster; Louis didn’t know.

“Yes?”

There was a snap in her voice. Louis jumped. He said, “I need a voice-programmed screen and a tape to tell me the characteristics of scrith.”

She frowned. “I don’t know what you mean. Voice-programmed?”

“I want the tape to read to me out loud.”

Harkabeeparolyn stared, then laughed. She tried to strangle the laugh, and couldn’t; and it was too late anyway. They were the center of attention. “There is no such thing. There never has been,” she tried to whisper, but the giggle bubbled up and made her voice louder than she wanted. “Why, can’t you read?”

Blood and tanj! Louis felt the heat rising in his ears and neck. Literacy was admirable, of course, and everybody learned to read sooner or later, at least in Interworld. But it was no life or death matter. Every world had voice boxes! Why, without a voice box, his translator would have nothing to work with!

“I need more help than I thought. I need someone to read to me.”

“You need more than you paid for. Have your master renegotiate.”

Louis wasn’t prepared to risk bribing this embarrassed and hostile woman. “Will you help me find the tapes I need?”

“You’ve paid for that. You’ve even bought the right to interrupt my own researches. Tell me just what you want,” she said briskly. She tapped at keys, and pages of strange script jumped on her screen. “Characteristics of scrith? Here’s a physics text. There are chapters on the structure and dynamics of the world, including one on scrith. It may be too advanced for you.”

“That, and a basic physics text.”

She looked dubious. “All right.” She tapped more keys. “An old tape for engineering students on the construction of the rim transport system. Historical interest only, but it might tell you something.”

“I want it. Did your people ever go under the world?”

Harkabeeparolyn drew herself up. “I’m sure we must have. We ruled the world and the stars, with machines that would make the Machine People worship us if we had them now.” She played with the keyboard again. “But we have no record of that event. What do you want with all this?”

“I don’t quite know yet. Can you help me trace the origin of the old immortality drug?”

Harkabeeparolyn laughed, softly this time. “I don’t think you can carry that many book spools. Those who made the drug never told their secret. Those who wrote books never found it. I can give you religious spools, police records, confidence games, records of expeditions to various parts of the world. Here’s the tale of an immortal vampire who haunted the Grass Giants for a thousand falans, growing uncomfortably cunning with the years, until—”

“No.”

“His hoard of the drug was never found. No? Let me see… Ktistek Building joined the Ten because the other buildings ran out of the drug before Ktistek did. A fascinating lesson in politics—”

“No, forget it. Do you know anything about the Great Ocean?”

“There are two Great Oceans,” she informed him. “They’re easy to pick out on the Arch at night. Some of the old stories say the immortality drug came from the antispinward Ocean.”

“Uh-huh.”

Harkabeeparolyn smirked. The small mouth could look prissy. “You are naive. One can pick out just two features on the Arch with the naked eye. If anything valuable came from far away and comes no more, somebody will say that it came from one of the Great Oceans. Who can deny it, or offer another origin?”

Louis sighed. “You’re probably right.”

“Luweewu, how can these questions possibly be connected?”

“Maybe they can’t.”

She got the spools he’d requested, and another: a book for children, tales of the Great Ocean. “I can’t think what you’ll do with these. You won’t steal them. You’ll be searched when you leave, and you can’t carry a reading machine with you.”

“Thank you for your help.”

He needed someone to read to him.

He didn’t have the nerve to ask random strangers. Perhaps a nonrandom stranger? There had been a ghoul in one of these rooms. If ghouls in the shadow farm knew of Louis Wu, perhaps this one did too.

But the ghoul was gone, leaving only her scent.

Louis dropped into a chair in front of a reading screen and closed his eyes. The useless spools bulged in two of his vest pockets. I’m not licked yet, he thought. Maybe I can find the boy again. Maybe I can get Fortaralisplyar to read to me, or to send someone. It’ll cost more, of course. Everything always costs more. And takes longer.

The reading machine was a big, clumsy thing, moored to the wall by a thick cable. The manufacturer certainly hadn’t had superconducting wire. Louis threaded a spool into it and glared at the meaningless script. The screen’s definition was poor, and there was no place for a speaker grid. Harkabeeparolyn had told the truth.

I don’t have time for this.

Louis stood up. He had no choices left.

The roof of the Library was an extensive garden. Walks spiraled out from the center, from the top of the spiral stairs. Giant nectar-producing flowers grew in the rich black soil between the walks. There were small dark-green cornucopias with tiny blue flowers in the mouths, and a patch of weenie plant in which most of the “sausages” had split to give birth to golden blossoms, and trees that dropped festoons of greenish-yellow spaghetti.

The couples on the scattered benches gave Louis his privacy. He saw a good many blue-robed librarians, and a tall male librarian escorting a noisy group of Hanging People tourists. Nobody had the look of a guard. No ramps led away from the Library roof: there was nothing to guard, unless a thief could fly.

Louis intended a poor return for the hospitality he’d been given. True, he’d bought that hospitality… but it bothered him.

The water condenser rose from the roof’s edge like a sculptured triangular sail. It drained into a crescent-shaped pond. The pond seethed with City Builder children. Louis heard his name, “Luweewu!” and turned in time to catch an inflated ball against his chest.

The brown-haired boy he’d met in the map room clapped and shouted for the ball’s return.

Louis dithered. Warn him to leave the roof? The roof would soon be a dangerous place. But the kid was bright. He might be bright enough to see the implications and call for guards.

Louis threw the wet ball back at him, and waved, and moved away.

If only he could think of a way to clear the roof entirely!

There were no guardrails at the edge of the roof. Louis walked with care. Presently he circled a clump of small trees whose trunks seemed to have been wrung like washcloths, and found himself in a place of reasonable privacy. There he used his translator.

“Hindmost?”

“Speaking. Chmeee is still under attack. He has retaliated once, by melting one of the great ship’s large swiveling projectile launchers. I cannot guess at his motives.”

“He’s probably letting them see how good his defenses are. Then he’ll deal.”

“What will he deal for?”

“Even he doesn’t know that yet. I doubt they can do much for him except introduce him to a female or three. Hindmost, there’s no way I can do any research here. I can’t read the screens. I’ve got too much material anyway. It’d take me a week.”

“What might Chmeee accomplish in a week? I dare not stay to find out.”

“Yah. What I’ve got is some reading spools. They’ll tell us most of what we want to know, if we can read them. Can you do anything with them?”

“I think it unlikely. Can you furnish me with one of their reading machines? With that I could play the tapes on the screen and photograph them for Needle’s computer.”

“They’re heavy. They’ve got thick cables that—”

“Cut the cables.”

Louis sighed. “Okay. Then what?”

“Already I can see the floating city through the probe camera. I will guide the probe to you. You must remove the deuterium filter to expose the stepping disc. Have you a grippy?”

“I don’t have any tools at all. What I’ve got is a flashlight-laser. You tell me where to slice.”

“I hope this is worth losing half my fuel source. Very well. If you can secure a reading machine, and if it will pass through the opening to the stepping disc, well and good. Otherwise, bring the tapes. Perhaps there is something I can do.”

Louis stood at the rim of the Library roof and looked down past his toes, into the textured dusk of the shadow farm. At the shadows edge was noonday light. Rectangle-patterned farmland ran away from him. The Serpent River curled away to port and disappeared among low mountains. Beyond the mountains were seas, flatlands, a tiny mountain range, tinier seas, all bluing with distance… and finally the Arch rising up and up. Half hypnotized, Louis waited beneath the bright sky. There was nothing else to be done. He was barely aware of time passing.

The probe came out of the sky on a breath of blue flame. Where the nearly invisible fire touched the rooftop, the plants and soil became an orange inferno. Small Hanging People and blue-robed librarians and wet children ran screaming for the stairwell.

The probe settled into the flame and toppled on its side, slowed by attitude jets. There were tiny jets all around the upper rim, and the big jet underneath. It was twenty feet long and ten feet thick, a cylinder made lumpy by cameras and other instruments.

Louis waited until the fires had mostly gone out. Then he waded through coals to the probe. The roof was empty, as far as he could tell — empty even of bodies. No dead. Good.

The voice of his translator guided him as he cut away the thick molecular sieve in the top of the probe. Presently he had exposed a stepping disc. He asked, “Now what?”

“I’ve reversed the action of the stepping disc in the other probe and removed the filter. Can you get a reading machine?”

“I’ll try. I don’t like any of this.”

“In two years it won’t matter. I give you thirty minutes. Then come, bringing whatever you have.”

A score of blue-robed librarians had almost decided to come after him when Louis appeared in the stairwell. His hood was pulled over his face. The bits of heavy metal they fired at him bounced from his impact armor, and he came on in a jerky step-stop-step walk.

The fusillade slowed and stopped. They retreated before him.

When they had gone far enough, Louis sliced through the top of the stairway below him. The spiral staircase had been moored only at top and bottom. Now it compressed like a spring, ripping side ramps from doorsills. Librarians hung on for dear life. Louis had the top two floors to himself.

And when he turned to the nearest reading room, Harkabeeparolyn was blocking his path with an ax in her hands.

“Once again I need your help,” Louis said.

She swung. Louis caught the ax as it rebounded from the join of his neck and shoulder. She thrashed, trying to wrench it from his grip.

“Watch,” he said. He waved the laser beam through the cable that fed a reading machine. The cable spurted flame and fell apart, sparking.

Harkabeeparolyn screamed, “Lyar Building will pay dearly for this!”

“That can’t be helped. I want you to help me carry a reading machine up to the roof. I thought I was going to have to cut through a wall. This is better.”

“I won’t!”

Louis waved the light through a reading machine. It burned after falling apart. The smell was horrible. “Say when.”

“Vampire lover!”

The machine was heavy, and Louis wasn’t about to let go of the laser. He backed up the stairs; most of the weight was in Harkabeeparolyn’s arms. He told her, “If we drop it we’ll have to go back for another one.”

“Idiot!… You’ve already… ruined the cable!”

He didn’t answer.

“Why are you doing this?”

“I’m trying to save the world from brushing against its sun.”

She almost dropped it then. “But — but the motors! They’re all back in place!”

“So you already knew that much! It’s too little too late. Most of your spaceships never came back. There aren’t enough motors. Keep moving.”

As they reached the roof, the probe lifted and settled beside them on attitude jets. They set the machine down. It wasn’t going to fit. Louis gritted his teeth and sliced the screen free of the rest of the machine. Now it would fit.

Harkabeeparolyn just looked at him. She was too exhausted to comment.

The screen went into the gap where the molecular filter had been, and vanished. What remained, the guts of the machine, was much heavier. Louis managed to heave one end into the gap. He lay down on his back and used his legs to push it inward until it too vanished.

“Lyar Building had nothing to do with this,” he told the librarian. “They didn’t know what I had in mind. Here.” He dropped a swatch of dull black cloth beside her. “Lyar Building can tell you how to fix water condensers and other old machines with this. You can make the whole city independent of the Machine People.”

She watched him with eyes full of horror. It was hard to tell if she heard.

He eased himself feet first into the probe.

And out head first into Needle’s cargo hold.