Ringworld's Children

rolled-up landscape. Their food would grow there too, water and air and wastes recycled, a locked ecology. No pheromones from breeder housing would reach the flight control complex. The breeders were not to love us; they would not be aware of us at all. Any protector violating the ban must die.

'Of course there was natural selection at work. Many breeders would die, did die without the company of protectors.' Proserpinas eyes sought theirs. 'Even now, four million falans evolved, dont you Ball Worlders sometimes need the companionship of something greater than yourselves?'

Roxanny said, 'No.'

'I find records of scores of religions.'

'Weve outgrown them,' Roxanny said.

After a moments pause, Proserpina said, 'Stet. Many breeders died for lack of our company, but less every generation. Again, many protectors found we must smell or touch our own kind. Many found ways to enter breeder housing, and died when they were caught. Others stopped eating. In the first thousand years we lost half our number. Replacing them from breeder stock was a chancy thing. Natural selection took its toll.

'What emerged at the end of three hundred and fifty thousand falans of travel, was a race that can live without the smell of our own blood line constantly in our nostrils.

'We veered away from the target world. A colony there had failed, but we could not know how badly. We might find protectors already in place, and our ship was a fragile bubble. We believed — Yes, Roxanny?'

'Earth?'

'Yes, your world, Earth. We could have had Earth. Your tree-of-life plants werent growing right. Your protectors died. Their descendants were mutating in many directions. We didnt know that. I learned too little of the Earth colony before your evolved breeders began blasting radio waves at the stars. By then—'

Proserpina blinked at them; started over. 'We arrived in the local neighborhood. We found worlds we might take, but our ambitions were greater than that. We chose a system with a gas giant planet huddled close up against its star. We surmise it formed far out in the disk that became the planets. Then it was drawn in over the billions of years, eating lesser worlds as it came. Thus we found a planetary system already cleared out for our convenience, and most of the mass gathered in a single body, a mass of almost twenty Jupiters, Roxanny.

'So we built. We met difficulties working that close to a sun, but we could use the suns magnetic fields to confine the masses we worked with, particularly the hydrogen we needed for fusion motors to spin up the ring.

'Stars that can generate extensive planetary systems form in clusters. There were stars with planets around us where we stopped, and some were Pak-like or close to it. We identified those that might evolve dangerous enemies. We collected local ecologies and settled them on maps of their worlds.

'We never approached Earth, Roxanny. We were afraid. We studied the system intensively at long range. The Map of Earth became home to our own breeders. We needed fifty thousand falans to build an ecology into the Ringworlds inner surface, but we started there, with the Map of Earth as a test bed.'

'Whales,' Louis said. 'There are whales in the Great Ocean. Some protector must have gone to Earth.'

'It may have happened after I was isolated,' Proserpina said. 'Wembleth, are you keeping up with this?' Proserpina changed languages and spoke rapidly. She switched back: 'Later Ill show Wembleth maps of the sky, and diagrams. You two should try to tell him what a Ball World is. Roxanny, these maps of our world are prisons. We knew some of us would break the one law. We built the prisons first, to warn each other. Any felon would be isolated with a world to rule and a population all of her own kind, just as if theyd each conquered the Pak homeworld, but all made hostage to the majority.

'I was one of those.'

'Why?'

'Oh, Roxanny.' Proserpinas body language suggested impatience and bitter laughter. 'We thought we would win! Eleven of us thought we could take the Repair Center. Wed breed our descendants to all of the lines, and cull to keep our traits dominant. In a thousand years wed be safe, even if the power balance changed, even if an insurgence should kill us. We planned it all in an afternoon, and collected our resources as fast as ever we could. Even so, we were a little slow.

'They confined me on one of the Maps, not this one. They collected a hundred of my line and scattered them in pairs through this land. I must build a land they could live in. I must guide the breeders myself so that ultimately they meet and interbreed, or else inbreeding would destroy them. While I did all that, time passed me by. I was out of the loop. Others of my descendants lived among the Ringworlds expanding population, and their genes were hostage too.'

Proserpina fell silent. Louis asked, 'How long did it last? What stopped it?'

'A few hundred thousand falans — Im guessing, Luis. Wembleth, Roxanny, you dont understand? On the Ringworld we built, a breeder population expanded to a trillion. At some point they became a chaos of mutations. Mutations are of no use to a protector; they dont smell right. Luis asks me when the protectors stopped culling their tribes, and why. I witnessed too little. I dont know why. Im guessing even at when.

'I was a prisoner. I spent long periods in depression, noticing nothing. I never quite starved myself. When I was myself, I made telescopes but not probes. We were barred from intrusive investigations. With telescopes I could see nothing nearby, but I could study what was happening far up the arc. Meteors continued to be intercepted. An eyestorm formed; I guessed at the dynamics; I saw the storm dissipate. It meant that protectors were still doing repairs. Luis, what?'

'Depression. Sorry, I dont mean to interrupt—'

'How can I not notice when you want to speak?'

'These bouts of depression, do they make you miss things? Im wondering about the rim-wall attitude jets, and Fist-of-God Mountain.'

'Where is it?'

'Near the far ocean. It was a giant meteoroid impact, from underneath. It didnt leak much because the land was pushed up.'

'I would not have acted. This is work for the resident protector.'

'There was a fight for who would be resident protector.'

Roxanny and Proserpina stared at Louis. Then Proserpina moaned. 'Ive been remiss.'

Louis asked, 'Did your jailers give you tree-of-life?'

'Yes, but neutered. A virus causes the gene flip that makes a breeder a protector. The virus lives in tree-of- life root. Neutered tree-of-life will still feed me, will feed any protector, but it wont change a breeder. What made you ask that, Luis?'

'Just a thought.' Tree-of-life only grew in the Repair Center, as far as Louis knew. Apparently it had died out elsewhere. 'Is it easy to get rid of the protector virus?'

'Yes.'

'But you got more?'

'How did you know that? Yes, I filtered it from the air when it grew thick enough and scattered far enough, four hundred thousand falans after creation. I cultured the virus and grew it in my plants. I made a few servants then, not enough to be noticed, and sent them on errands. But they revolted, and I had to kill them, Luis, and the next time I tried it, it didnt work. My plants had been neutered again. I know not by what means, and the virus wasnt in the air any more. You ate tree-of-life tonight.'

Roxanny gasped. Louis gulped. He said, 'Tasted like a yam. I think it probably is a yam, Roxanny. Proserpina, when did it happen?'

'Something more than a million falans after creation. You know what happened, dont you, Luis? Tell me.'

Louis shook his head. 'The protectors are gone. Thats all we know.'

Proserpina said, 'I understand now. Species differentiation has been extreme in the past two million falans. I can see how far your species has veered, Roxanny, under pressures that favor intelligence, hairlessness, swimming talent, and a two-legged run. My telescopes can observe the spill mountains. I went to visit them when I dared, when I was sure I was the last protector in these lands.

'Their people fission into incompatible species under nearly identical conditions. Ive tapped the heliograph