The Last Hero by Terry Pratchett

?"
    "I'm not quite sure, sir. They may crash into the Disc, or they may shoot straight out into endless space."
    "And they need air..."
    "Yes, sir."
    Vetinari's arm moved through the outline of the world and a long forefinger pointed.
    "Is there any air here ?" he said.
    "That meal," said Cohen, "was heroic. No other word for it."
    "That's right, Mrs McGarry," said Evil Harry. "Even rat doesn't taste this much like chicken."
    "Yes, the tentacles hardly spoiled it at all!" said Caleb enthusiastically.
    They sat and watched the view. What had once been the world below was now a world in front, rising like an endless wall.
    "What're they, right up there?" said Cohen, pointing.
    "Thanks, friend," said Evil Harry, looking away. "I'd like the... chicken to stay down, if it's all the same to you."
    "They're the Virgin Islands," said the minstrel. "So called because there's so many of them."
    "Or maybe they're hard to find," said Truckle the Uncivil, burping. "Hur, hur, hur."
    "Ye can see the stars from up here," said Mad Hamish, "e'en though 'tis day."
    Cohen grinned at him. It wasn't often Mad Hamish volunteered anything.
    "They say every one of 'em's a world," said Evil Harry.
    "Yeah," said Cohen. "How many, bard?"
    "I don't know. Thousands. Millions," said the minstrel.
    "Millions of worlds, and we get... what? How old are you, Hamish?"
    "Whut? I were born the day the old thane died," said Hamish.
    "When was that? Which old thane?" said Cohen patiently.
    "Whut? I ain't a scholar! I canna remember that kinda stuff!"
    "A hundred years, maybe," said Cohen. "One hundred years. And there's millions o' worlds." He took a pull of his cigarette and rubbed his forehead with the back of his thumb. "It's a bugger."
    He nodded at the minstrel. "What did your mate Carelinus do after he'd blown his nose?"
    "Look, you really shouldn't think of him like that," said the minstrel hotly. "He built a huge empire... too big, really. And in many ways he was a lot like you. Haven't you heard of the Tsortean Knot?"
    "Sounds dirty," said Truckle. "Hur, hur, hur... sorry."
    The minstrel sighed. "It was a huge, complicated knot that tied two beams together in the Temple of Offler in Tsort, and it was said that whoever untied it would reign over the whole of the continent," he said.
    "They can be very tricky, knots," said Mrs McGarry.
    "Carelinus sliced right through it with his sword!" said the minstrel. The revelation of this dramatic gesture did not get the applause he expected.
    "So he was a cheat as well as a cry-baby?" said Boy Willie.
    "No! It was a dramatic, nay, portentous gesture!" snapped the minstrel.
    "Yeah, okay, but it's not exactly untying it, is it? I mean, if the rules said 'untying', I don't see why he should —"
    "Nah, nah, the lad's got a point," said Cohen, who seemed to have been turning this one over in his mind. "It wasn't cheating, because it was a good story. Yeah. I can understand that." He chuckled. "I can just imagine it, too. A load of whey-faced priests and suchlike standin' around and thinkin', 'that's cheating , but he's got a really big sword so I won't be the first to point this out, plus this damn great army is just outside'. Hah. Yeah. Hmm. What did he do next?"
    "Conquered most of the known world."
    "Good lad. And after that?"
    "He... er... went home, reigned for a few years, then he died and his sons squabbled and there were a few wars... and that was the end of the empire."
    "Children can be a problem," said Vena, without looking up from carefully embroidering forget-me-nots around BURN THIS HOUSE.
    "Some people say you achieve immortality through your children," said the minstrel.
    "Yeah?" said Cohen. "Name one of your great-granddads, then."
    "Well... er..."
    "See? Now, I got lots of kids," said Cohen. "Haven't seen most of 'em... you know how it is. But they had fine strong mothers and I hope like hell they're all living for themselves, not for me. Fat lot of good they did your Carelinus, losin' his empire for