Ringworld by Larry Niven

Louis Wu. "That's why nobody ever found the puppeteer world."
    "That was part of the reason."
    "We searclied every yellow dwarf sun in known space, and a number outside it. Wait a minute, Nessus. Somebody would have found the farmin plancts. In a Kemplerer rosette."
    "Louis, they were searching the wrong suns."
    "What? You're obviously from a yellow dwarf."
    "We evolved under a yellow dwarf star somewhat like Procyon. You may know that in half a million years Procyon will expand into the red giant stage."
    "Finagles heavy handl Did your sun blow up into a red giant?"
    "Yes. Shortly after we finished moving our world, our sun began the proem of expandon. Your fathers were still using the upper thigh bone of an antelope to crack skulls. When you began to wonder where our world was, you were searching the wrong orbits, about the wrong Suns.
    "We had brought suitable worlds from nearby systems, increasing our agricultural worlds to four and setting them in a Kemplerer rosette. It was necessary to move them all when the sun began to expand, and to supply them with sources of ultraviolet to compensate for the reddened radiation. You will understand that when the time came to abandon galaxy, two hundred years ago, we were well prepared. We had had practice in moving worlds."
    The rosette of worlds had been expanding for some tme. Now the puppeteer world glowed beneath their feet, rising, rising to engulf them. Scattered stars in the black seas had expanded, to become scares of small islands. The continents burned like sunfire.
    Long ago, Louis Wu had stood at the void edge of Mount Lookitthat. The Long Fall River, on that world, ends in the tallest waterfall in known space. Louis's eyes had followed it down as far as they could penetrate the void mist. The featureless white of the void itself had grasped at his mind, and Louis Wim, half hypnotized, had sworn to live forever. How else could he see all there was to we?
    Now he reaffirmed that decision. And the puppeteer world rose about him.
    "I am daunted," said Speaker-To-Animals. His naked pink tail lashed in agitation, though his furry face and burry voice carried no emotion. "Your lack of courage had deserved our contempt, Nessus, but our contempt has blinded us. Truly you are dangerous. Had you feared us enough, you would have ended our race. Your power is terrible. We could not have stopped you."
    "Surely a kzin cannot fear an herbivore."
    Nessus had not spoken mockingly; but Speaker reacted with rage "What sapient being would not fear such power?"
    "You distress me. Fear is the brother of hate. One would expect a kzin to attack what he fears."
    The conversation was getting sticky. With the Long Shot millions of miles in their wake, and known space hundreds of light years away, they were all very much within the power of the puppeteers. It the puppeteers found reason to fear them -- Change the subject, fast! Louis opened his mouth.
    "Hey," said Teela. "You people keep tallang about Kemplerer rosettes. What's a Kemplerer rosette?"
    And both aliens started to answer, while Louis wondered why he had thought Teela shallow.

CHAPTER 6 -- Christmas Ribbon
    "The joke's on me," said Louis Wu. "Now I know where to find the puppeteer world. Very nice, Nessus. You kept your promise."
    "I told you that you would find the information more surprising than useful."
    "A good joke." said the kzin. "Your sense of humor surprises me, Nessus."
    Below, a tiny eel-shaped island surrounded by a black sea. The island rose like a fire salamander, and Louis thought he could pick out tall, slender buildings. Obviously aliens would not be trusted on the mainland.
    "We do not joke," said Nessus. "My species has no sense of humor."
    "Strange. I would have thought that humor was an aspect of intelligence."
    "No. Humor is associated with an interrupted defense mechanism."
    "All the same --"
    "Speaker, no sapient being ever interrupts a defense mechanism."
    As the ship dropped the lights resolved: sun-panels,