"We use the sun for thrust, up to a few meters per second squared by Interworld measurement. Beyond that—" Streamlines formed. The Ringworld moved on alone, the sun lost. "Flux of interstellar matter through the Ringworld can be steered to the axis to undergo fusion. The jet from the sun gives more fuel. A fusion exhaust confined by magnetic fields replaces the sun, bathes the Ringworld in light, and serves as a ramjet too. The Ringworld survives. We can continue to accelerate."

"Drawbacks?"

"Deceleration would be difficult but not impossible. Fields could be adjusted to thrust forward. Tides would shift."

Tunesmith waited.

"When we stopped, there would be no sun." Proserpina shrugged; the picture distorted. "It doesnt matter. We cant even begin. The sun grows too hot if we try to accelerate it. The shadow-square ring can be pulled almost closed, for shielding, but if the shadow squares fell behind or were pulled ahead, landscape would be charred.

"Worst, its too slow," Proserpina said. "The suns gravitational pull isnt enough. I can manipulate the suns magnetic fields to pull harder on the Ringworld, and it still isnt enough. Alien intruders still follow. I cant think of a way to leave them behind."

"Its the wrong principle," Tunesmith said. "You didnt know. You lack information. Did Louis Wu speak of Carlos Wus medical system? Or the spacecraft we stole from the Kzinti?"

"No."

"Ill give you details when I need to. Meanwhile — those protectors vicious enough to hold the Repair Center have not always been diligent. Theyve allowed meteor impacts, eyestorms, erosion, and sometimes an exposed sea bottom. That fool bloodsucker left thousands of places where the Ringworlds foundation shows through. I need you and your allies and servants to find these places and shake a dust into them. I have been working with others of my own kind, with the Ringworld-wide network of Ghoul species; but I havent been able to reach enough of these breaches. We move too slowly."

"What is this dust? What does it do?"

"You need only know—"

"I must judge for myself!"

"I dont want an equal partner, Proserpina! The dust spreads itself through scrith, but first the scrith must touch it. How can we put more of it in contact with the Ringworld floor?"

"My servants in the spill mountains," Proserpina said, "are useless on the flats. They suffocate. Theyll spread dust along the spill mountain edges, on the rim wall, if you can get the dust to them. Theyll travel by balloon from peak to peak."

"Good. My own spill mountain protectors have been doing that. What else?"

"Water folk," Proserpina said. "Well use them. We need to reach the spill pipe system that circulates sea bottom sediment—"

"Hup."

"Yes, flup. We use that word too. Flup accumulates in the bottoms of the seas. Without our tending, it would stay there. Topsoil all through the Ringworld would be lost under the seas in a few thousand years. Weve set in place a circulation system of spillpipes that runs under the scrith floor and up the outside of the rim wall, to fall over the edge. It becomes spill mountains. Ultimately it replenishes the earth. If your dust can be introduced into the seabottoms, can it spread into the scrith from there?"

"Yes."

"How long will it take?"

"If we begin now, less than two falans."

CHAPTER 19

Wakening

He ate, and he hid.

Louis crawled among the plants, working his way deep into the jungle. He lived on his belly, reaching out of the shadows to dig for the yellow roots. The hanging garden was too exposed. He couldnt do anything about that; he couldnt leave his food source. Every hominid species on Earth and the Ringworld must have kept at least this one trait: a breeder turning into a protector would hide lest other protectors find him.

Shadow and light: days flickered by.

Nothing seemed to be looking for him. He wondered about that. A loose protector ought to be a matter of concern. It suggested that the Ringworlds protectors had other concerns: they were all involved in the Fringe War problem, ignoring the usual lethal dominance games. It must be bad. He should be helping.

Changing body, restless mind. Why was he eating tree-of-life at an effective age of twenty or so? That had an obvious answer, but the implications were serious.

The doc had given him the symptoms, but hadnt really made him an adolescent. Why not?

Tunesmith had opened Carlos Wus experimental autodoc and spread it out like an autopsy patient, to solve all its puzzles. Hed kept Louis Wu in there much longer than Louis needed, to test his notions, and for another reason. The docs nanotechnology had rewritten Louis Wus genetics, possibly over and over, until he was ready to become a protector at any time Tunesmith chose.

If Tunesmith had studied nanotechnology in such detail, by now hed know that subject better than any mind in known space. What was he doing with it?

And that too was obvious, given the theft of Long Shot.

Louiss mind wandered away, fizzing with inspiration, seeking other puzzles.

Where was the Hindmost? Aboard Hot Needle of Inquiry. A ship built like a glass bottle could still be furnished with hidden control rooms. Where was Hot Needle of Inquiry? It didnt matter. Louis could reach the ship by stepping disk, and that was all that mattered, unless — was it flightworthy? Hed have to learn.

Why was Tunesmiths nose so large, when Proserpinas was almost flat?

Did Louis Wu have children or N-children among the ships of the Fringe War?

Where was Long Shot? Tunesmith might be studying the ship where hed worked on Needle and the autodoc, in the Launch Room beneath the Map of Mons Olympus. The Launch Room was roomy enough. It was the first place Louis would look, if he ever got over this… torpor. It felt like he was thinking very fast, but his mind was like ten thousand butterflies in a field, lighting everywhere, going nowhere. His body… he couldnt tell.

He hid, and he ate.

Where had Roxanny taken Wembleth? Shed fled from Louis Wu and his protector allies. Of course she must have burned her bridges behind her: changed settings on the stepping disks, maybe burned out the last one before hiding herself. How would he ever find them?

One hundred and fifty-one days flickered past. Then it was as if hed wakened from a doze.

He stayed where he was, half buried in dirt and plant stalks. His hands moved over his face and his body, finding a new shape. Swollen joints. Vanished testicles, penis shrunken to nothing. His skull had softened, expanded, hardened again, leaving a minor crest of bone. His face was a hard mask, lips fused to gums and ossified. His nose was enlarged. Hed look like a clown. And his sense of smell had become almost magical.

Hah! Hed solved it, the problem of the noses.

A human nose forms a kind of hood: it will hold a bubble of air for a swimmer. Apes dont have the hooded nostrils because they dont swim. Humans have evolved halfway in every direction, including the aquatic: most of their skin is bare, like the smooth skin of a dolphin.

Fate really did intend mankind to swim.

Breeders lose most of their sense of smell because it would drive them crazy. They would kill any stranger who came near their children, even doctors and teachers. They would protect their children from everything, driving them crazy.

Louiss nose told him that the Penultimates arcology-sized refuge was empty of enemies. The only life here was burrowers and insect analogues, and an old scent that went straight to his hindbrain.

He looked at the watch tattooed on the back of his hand. Swollen knuckles and wrist bones distorted the digital display. It was telling Canyon time. He did the math and found that hed been dawdling for two falans. Far too long. But it was right, hed counted one hundred fifty-one thirty-hour days. An old ARM record said that Jack Brennan had changed to a protector much faster than that.