Ringworld's Children

by Larry Niven

  "Some are only observers," Proserpina said. "Some are arrayed for war. Badly. The ARM would win if they struck there and there..." Her voice wandered off. "And wreckage from this ship or this one might strike the Ringworld. That tail design confines antimatter fuel, doesn't it? Has Tunesmith considered destroying all of these fleets?"

  "Tunesmith considers everything."

  "But I don't know his tools. He must be at work on something! Something besides mere defensive meteor control. I won't know anything until I know what we can fight with. Or run with."

  Hanuman said, "Run?"

  "I speculate." Proserpina walked around the curve of the glowing wall. Under a glare of light were the bones of an ancient protector, laid out with some of his tools. The joints were swollen into knobs. Vertebrae in the back were fused.

  "They had already begun to mutate," she said. "Do you know that we kill mutants? Do you still do that?"

  "Of course, if they smell wrong, or behave wrong."

  "This one was very good at what he did. Look at the state of the bones, the scarring from mere age. He must have survived tens of thousands of falans. Hanuman, should we have loosed our predators?"

  "No."

  "But these who were our own shape have occupied every ecological niche we didn't fill." She looked hard at Hanuman. She'd almost managed to ignore his mutant smell. "I see your point. Not just scavengers like this one, but brachiators like you. Mutations and evolution are good, if only you can stop it now, always now, so that your own kind need not change."

  Hanuman didn't answer. She was only stating the obvious.

  But Tunesmith spoke. "Your kind, your original Pak, did not survive. That's what mutations and evolution are for, Proserpina. Something almost of your shape has multiplied into the tens of trillions. You don't like some of us? When did you ever like all of your neighbors?"

  He was standing atop a chair on a boom just above her head. He could have nailed her in an instant. Too clever, too quick.

  Proserpina said, "Bet. Even odds we'll be dead in nineteen falans, if I read these patterns right. You've studied them longer. Hello, Tunesmith."

  Tunesmith leapt down. "Hello, Proserpina, revered ancestor. Are your guests safe?"

  "I see this as more urgent than their lives. You have been meddling with our basic design!"

  "Yes, but not quickly enough. I need all the help I can get."

  "What design changes have you made? What changes do you contemplate?"

  "What would be your approach to dealing with the Fringe War?"

  "I might have tried... can you give me a way to make pictures?"

  Tunesmith set his chair swinging near the elliptical wall. Now the starscape was gone, and the wall was deep blue. Tunesmith waved at the wall: white lines appeared.

  Proserpina jumped to another chair. She waved shapes to life. Sun. Shadow squares. Ringworld. They were white lines and curves, and then they were photographically realistic views. Proserpina's arms moved like a concert master's. The sun took on detail: magnetic fields cradled the interior. The fields changed: squeezed. The sun's south magnetic pole curdled, churned, then sprayed light.

  "I might have tried this," Proserpina said. "When we built the Ringworld, we set a superconductor network within the foundation structure. We can manipulate magnetic fields." The sun's south pole jetted X-ray-colored flame. Slowly the sun moved north, leaving the Ringworld behind. Its gravity pulled, faint lines on the blue wall, and the Ringworld followed.

  "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 doesn't matter. We can't 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, it's too slow," Proserpina said. "The sun's gravitational pull isn't enough. I can manipulate the sun's magnetic fields to pull harder on the Ringworld, and it still isn't enough. Alien intruders still follow. I can't think of a way to leave them behind."

  "It's the wrong principle," Tunesmith said. "You didn't know. You lack information. Did Louis Wu speak of Carlos Wu's medical system? Or the spacecraft we stole from the Kzinti?"

  "No."

  "I'll give you details when I need to. Meanwhile--those protectors vicious enough to hold the RepairCenter have not always been diligent. They've allowed meteor impacts, eyestorms, erosion, and sometimes an exposed sea bottom. That fool bloodsucker left thousands of places where the Ringworld's 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 haven't 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 don't 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. They'll spread dust along the spill mountain edges, on the rim wall, if you can get the dust to them. They'll travel by balloon from peak to peak."

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

  "Water folk," Proserpina said. "We'll 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. We've 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 couldn't do anything about that; he couldn't 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 Ringworld's 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 ans
wer, but the implications were serious.

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

  Tunesmith had opened Carlos Wu's experimental autodoc and spread it out like an autopsy patient, to solve all its puzzles. He'd kept Louis Wu in there much longer than Louis needed, to test his notions, and for another reason. The 'doc's nanotechnology had rewritten Louis Wu's 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 he'd 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.

  Louis's 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 didn't matter. Louis could reach the ship by stepping disk, and that was all that mattered, unless--was it flightworthy? He'd have to learn.

  Why was Tunesmith's nose so large, when Proserpina's 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 he'd 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 couldn't tell.

  He hid, and he ate.

  Where had Roxanny taken Wembleth? She'd 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 he'd 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. He'd look like a clown. And his sense of smell had become almost magical.

  Hah! He'd 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 don't have the hooded nostrils because they don't 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.

  Louis's nose told him that the Penultimate's 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 he'd been dawdling for two falans. Far too long. But it was right, he'd 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.

  Something had slowed his metamorphosis.

  He tried to stand up, already guessing the answer.

  He couldn't stand straight. He'd been half-healed when he began to eat yellow root. The injuries were embedded in the regrowth pattern. He'd become a protector, but crippled. His knee, leg, hip, and ribs on the left side were twisted out of true. His body was nearly fat free, the fat burned out of him during too long an estivation.

  He limped through the hanging garden, learning how to move all over again. A protector who couldn't fight. He reached for something badger-like and caught its leg only because it was so slow. He ate it in haste, and judged it was enough.

  A few ramps below was the scorched and half-melted service stack. He limped down and had a look. It had cooled, of course. He tried to pop the controls open, but melted metal had fused it shut.

  He climbed painfully onto the stepping disk. Nothing happened.

  His fist slapped the rim hard.

  Mars! He twisted and reached up to slap both hands against the inverted stepping disk before he could fall away. A moment later he was in a handstand in a field of high grass. He rolled to his feet quick (where was Tunesmith?) and found himself under a blue hemisphere, in the tree-of-life garden where he'd killed Teela Brown.

  Tunesmith?

  Nowhere.

  He popped the stepping-disk controls open and began to play. First things first.

  There was a mile-long craft on the GreatOcean. Hidden Patriarch had brought Kzinti to conquer the Map of Earth, centuries ago, and on that ship was a stepping disk. Louis didn't remember its code, but he found it.

  Hidden Patriarch. He flicked in wire-tense, ready to fight or die.

  Nothing came at him. He could see a bronze fractal spider web looking at him from a rusted iron wall: one of the Hindmost's webeyes. Otherwise the location didn't seem to be guarded.

  He'd left Hidden Patriarch almost beneath the Ringworld's starboard rim wall. Such a view could reduce a man to the size of a proton. Mountains as big as Everest lined its base, green with riotous life. Spill mountains were all seabottom muck, all fertilizer.

  The librarians hadn't moved the ship. The Hindmost said they'd been returned home. Hidden Patriarch might well be empty.

  Louis popped the controls, taking this disk out of the network. Now he was unreachable.

  For a few moments now, Louis only thought. His memories were muzzy--a long lifetime of breeder memories. His memories of this last hour were diamond clear.

  Long ago, it seemed, he'd studied a map of the Hindmost's stepping-disk system. Now he reached back into those memories to find settings and placements for various locations. They were mostly lost... but what he needed was a disk only recently put into service. Thought and memory gave him the code by which the Hindmost designated stepping disks. Wouldn't Tunesmith keep that system? It would give Louis a handful of settings to try.

  He'd better have a pressure suit.

  He popped aboard Hot Needle of Inquiry and yelled, "Hindmost's Voice! It's Louis!" Despite changes in his throat structure he made himself sound like Louis Wu.

  "Don't move. You are not Louis Wu," said a flat voice like the Hindmost's.

  Louis didn't move. He was in the crew cabin. For an instant he considered familiar food, a shower, and a change of clothes, but it just didn't matter. He said, "Tell the Hindmost Louis Wu has become a protector. I need to talk to him."

  "Louis? I warned you!" said the same voice.

  "I knew. Don't tell me where you are. I've come for a pressure suit. Have you been watching the Fringe War? Has anything happened?"

  "An antimatter missile destroyed one of the ramjets on the rim wall," the puppeteer's voice said. "Twenty-eight Ringworld days ago. The explosion was tremendous, not just antimatter but kilotonnes of confined plasma under fusion. Spill mountains melted. I couldn't learn what faction did that. I thought chaos would follow. I made ready to depart, but nothing happened."

  "Those attitude jets always were too vulnerable. Tunesmith must have set up something else by now." Louis's mind ranged ahead of his words. "The Ringworld builders never did want rim wall ramjets as anything more than a tem
porary fix and a safety feature. They built the superconductor grid to move the system magnetically, push against the sun. Tunesmith controls that."

  "You're guessing."

  "I guess good. I'm a protector. Free me, Hindmost, and I'll get off your property."

  "What's it like?" the Hindmost asked.

  "I feel confined. I'm crippled," Louis said. "I can't fight and can't run. I can think faster than I ever did before. I see more answers. That's confining too, in a way. If I see the right answer every time, there're no choices.

  "Tunesmith has a plan. I won't interfere unless he threatens my N-children, but I should talk to him. It's just that there are things I have to do first. What about you? Do you have a plan?"

  "Run away when I see a chance."

  "Good. Do you remember where Tunesmith worked cm Needle? Do you have webeye cameras in there?"

  "Beneath Mons Olympus."

  "Is Long Shot there? Is it functional?"

  "He took the ship apart and put it back together. He hasn't tested it since."

  "What about Carlos Wu's autodoc?"

  "It hasn't been touched."

  "It's still spread out across the floor?"

  "Yes."

  "Watch for me to cause a distraction. Then get the autodoc aboard Long Shot in working condition. Can you do it?"

  The scream of a demented orchestra. "Why would I even consider committing burglary on a protector's turf!"

  "But you'll have a protector on your side. Hindmost, we are under a deadline. Tunesmith will not consider your convenience. He will act as soon as he can, because he can't predict when the Fringe War will go to hell. If we can't get off the Ringworld soon, you'll lose your home forever, and so will I, and worse."

  Into the silence that followed, Louis said, "You're thinking you could hold me prisoner until you turn me over to Tunesmith. Buy something with that. Shall I tell you why you can't do that? Do you remember three chairs in the Meteor Defense Room, on booms?"

  "I remember."