Ringworld's Children by Larry Niven

sent the signal to deploy the double-X-large meteor plug. Tell me what you see, all three of you. Be free to interrupt each other, I can sort your voices."
    A lamp lit above the target.
    It didn't look much brighter than a street lamp, but its size... Louis squinted past the glare. "Something unfolding. Tunesmith, it looks like fire salamanders mating... or a balloon inflating... it's bulking up into a shape like a sailing ship's life preserver. Jets firing at fusion temperatures. What have you got there, Tunesmith?"
    Acolyte: "It's settling. Slowing. A torus. It's much wider than the puncture, a thousand to two thousand klicks across. Was this what you wanted to hear?"
    Hanuman: "The scrith foundation that holds the Ring together demonstrates tremendous tensile strength. I've done the numbers. The forces that hold scrith together would generate showers of quarks if pulled apart. A bag made of such material would be strong enough to confine a hydrogen fusion explosion. There's risk, Tunesmith, but it seems to be holding."
    Acolyte: "It's settling--"
    Louis: "--enclosing the puncture. Leaving the puncture exposed like a bull's-eye on a target. I'm guessing your balloon stands fifty miles tall, so it'll confine the atmosphere as long as it holds."
    Hanuman: "Tunesmith, how good an insulator is a scrith balloon? We wouldn't see it if it weren't leaking energy. When it cools enough, it'll collapse. Tunesmith, it will leak air. The ground beneath will be uneven."
    Answer came there none. Tunesmith's reaction was a Ringworld diameter away.
    So he must have spoken sixteen minutes ago. "Watch for the second package," the protector said. "Tell me if it settles inside the ring."
    Acolyte: "I don't see anything. Louis? Hanuman?"
    Louis: "There won't be a meteor trail--"
    Acolyte: "Rocket! I see it. Fusion, by its color. Settling slowly at the edge of the hole. It's down."
    Louis: "We're drifting too far. I can't see the puncture any more."
    Hanuman bent over the rim of the stepping disk. "I'll fix that. The next stepping disk is thirty degrees around the Ringworld arc. Ready?"
    They flicked.
    The Ringworld flowed beneath them. They'd jumped thirty degrees, about fifty million miles. Louis, looking ahead of him, found a line of white several worlds wide, and a brighter line peeping above its center. Acolyte said, "There it is. We can't see detail, Tunesmith. We won't be over it for half a day."
    Louis: "There's a zoom function in our faceplates. Tunesmith, I don't see any change. Your balloon plug is still inflated. Everything outside the balloon is fog. We've lost a... few percent of the Ringworld already."
    Around the edges of the fog, the land would be ravaged by shock waves running through air, sea, earth, and the scrith foundation. Weather patterns would be shattered.... Louis realized he was being optimistic. He was assuming that Tunesmith would plug the hole, stop the loss.
    He had once estimated the Ringworld's population at thirty trillion, with hominid species in every possible ecological niche. That vast plain of fog would be water droplets condensed by a drop in pressure. Ecologies under that fog blanket would be dehydrated and suffocating. Around it they'd soon be ravaged by climate change.
    But only if Tunesmith made a miracle.
    "I think a ship in stasis crashed to antispin of the puncture," Louis said. "I can't see it from here."
    Hanuman said, "We won't be over it for half a day. I'm going to flick us home."
    A moment later--plus a quarter hour--they were aboard Needle.
    Moments afterward, so was Tunesmith. "Hanuman, report," he said.
    "Your device deployed. It will hold for days, but it will leak. What are you expecting?"
    "I sent a reweaving system to make more scrith. I based my design on nanotechnology from the 'doc aboard Needle. A complicated matter, this. The system must replace not only the scrith floor but the superconductor grid within."
    Hanuman said, "There are species whose breeders evolved intelligent. Their