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 att.i.tude 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 att.i.tude 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 s.p.a.ceport 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 s.p.a.ce. 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?"

"n.o.body 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 pa.s.s. "Who are they? How did they find out about the danger?"

"n.o.body 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 s.e.x. "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 cl.u.s.tered 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 G.o.d's-eye view "south" along the sh.o.r.eline 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; n.o.body 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 s.p.a.ce until the Map of Kzin was a cl.u.s.ter 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-G.o.d 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-G.o.d, 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, G.o.d 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 s.p.a.ceports. All of the eleven ships have been rifled."