Ringworld's Children by Larry Niven Page A

secret to all of known space, didn't you, Louis? Enter and leave the Ringworld through any meteor puncture. Otherwise face a solar-pumped superthermal laser meteor defense."
    "If they find Needle," Louis said, "they'll have access to the stepping-disk network. Hindmost, is that technology easy to copy? The United Nations never had the chance. It's a lot more advanced than transfer booths."
    The Hindmost didn't answer, of course.
    Louis found himself staring at the display of the Other Ocean. The vast expanse of water and land looked like tapestry on a castle wall. Clusters of islands... continents; they'd be that big, as big as the maps in the Great Ocean, one of which was a one-to-one scale map of Earth. These were more thickly clustered, and they seemed all identical.
    "Hindmost, was the Ringworld built by Pak?"
    "I don't know, Louis."
    "I thought you might, by now. I wondered if there might be real Pak, somewhere among all these variant hominids. We've never seen anything of Pak but old bones."
    The puppeteer said, "We can deduce a good deal about Pak breeders. They slept or hid during the day and night. They hunted and did their business at twilight. They lived above a shoreline."
    Louis was startled. "How can you know all that?"
    "Your partial baldness suggests that your ancestors swam regularly, and I've watched you in the water, too. As for twilight, this Ringworld gets far more twilight than a planet would, and it's wholly unnecessary. Let me show you."
    The Hindmost boarded a chair, clumsily. His questing mouth found controls. The wall display jumped, became a featureless blue. The Hindmost began to draw in white lines. A blob of white: the sun. A circle: the Ringworld. A much smaller ring, concentric: thirty-odd shadow squares moving a little faster than orbit, held in a net of cables. "This is the way the Ringworld was designed," the Hindmost said. "A thirty hour day with ten hours blacked out, and more than an hour of a sun partly blocked. Instead--"
    He sketched in five long shadow squares sliding retrograde, against the Ringworld's spin. "This model would avoid the long, long twilight period and give equal day and night. The builders didn't want that. Whoever built the Ringworld must have wanted endless summers and long twilights. We surmise they were Pak protectors, and we surmise that the Pak world was like that."
    Louis studied the picture. Or else, he thought, they built an advanced model somewhere else.
    The Hindmost said, "I'm hungry. Will you keep watch?"
    "Hungry," the Kzin agreed. "Hurry."
    Time had slid by unnoticed. Louis realized he was half starved.
    A puppeteer must eat more often than a carnivore. The Hindmost was gone for most of an hour. He returned with jewels sparkling in a newly coifed mane. A float plate heaped with fodder followed him.
    "We'll regret the time we're wasting," he said. "Our last hours free from Tunesmith, but what can we do with them? My plans didn't reach far enough. Look, more warships."
    Three Kzinti, then an unfamiliar larger craft, then three more ARM ships danced around the inner ring of shadow squares, not firing yet.
    Louis said, "Acolyte, go feed yourself." Who wants to be around a hungry Kzin?
    Louis and the Hindmost watched the warships at play. "They won't all have stasis fields," Louis speculated. "Stasis fields are expensive and not too dependable, and of course they take a ship out of the action. So they'll be leery of the Ringworld's meteor defense, but Tunesmith turned that off, and they're starting to realize that. So," as three Kzinti ships began a long dive toward the Ringworld surface, "here come Kzinti to stop the first ARM ships, and more ARMs to stop them --tanj dammit!" A brilliant streak inside the atmosphere ended in a flash against desert.
    "That was an antimatter bullet," said the puppeteer.
    "And now it's a little eyestorm. Tanj, this isn't even the main event! What they want is Long Shot. Needle is nothing."
    "A Needle in a haystack? What you