The Last Continent

further back in time than that,” said the Dean. “Thousands of years, he says. No one’s grandfather is alive.”
    “That’s a lucky escape for Mister Stibbons senior, then,” said Ridcully.
    “ No , sir,” said Ponder. “Please! What I was trying to get across, sir, is that anything you do in the past changes the future. The tiniest little actions can have huge consequences. You might…tread on an ant now and it might entirely prevent someone from being born in the future!”
    “Really?” said Ridcully.
    “Yes, sir!”
    Ridcully brightened up. “That’s not a bad wheeze. There’s one or two people history could do without. Any idea how we can find the right ants?”
    “No, sir!” Ponder struggled to find a crack in his Archchancellor’s brain into which could be inserted the crowbar of understanding, and for a few vain seconds thought he had found one. “Because…the ant you tread on might be your own, sir!”
    “You mean…I might tread on an ant and this’d affect history and I wouldn’t be born?”
    “Yes! Yes! That’s it ! That’s right , sir!”
    “How?” Ridcully looked puzzled. “I’m not descended from ants.”
    “Because…” Ponder felt the sea of mutual incomprehension rising around him, but he refused to drown. “Well…er…well, supposing it…bit a man’s horse, and he fell off, and he was carrying a very important message, and because he didn’t get there in time there was a terrible battle, and one of your ancestors got killed—no, sorry, I mean didn’t get killed—”
    “How did this ant get across the sea?” said Ridcully.
    “Clung to a piece of driftwood,” said the Dean promptly. “It’s amazing what can get even on to remote islands by clinging to driftwood. Insects, lizards, even small mammals.”
    “And then got up the beach and all the way to this battle?” said Ridcully.
    “Bird’s leg,” said the Dean. “Read it in a book. Even fish eggs get transported from pond to pond on a bird’s leg.”
    “Pretty determined ant, then, really,” said Ridcully, stroking his beard. “Still, I must admit stranger things have happened.”
    “Practically every day,” said the Senior Wrangler.
    Ponder beamed. They had successfully negotiated an extended metaphor.
    “Only one thing I don’t understand, though,” Ridcully added. “ Who’ll tread on the ant ?”
    “What?”
    “Well, it’s obvious, isn’t it?” said the Archchancellor. “If I tread on this ant, then I won’t exist. But if I don’t exist, then I can’t have done it, so I won’t, so I will. See?” He prodded Ponder with a large, good-natured finger. “You’ve got some brains, Mister Stibbons, but sometimes I wonder if you really try to apply logical thought to the subject in hand. Things that happen stay happened. It stands to reason. Oh, don’t look so downcast,” he said, mistaking—possibly innocently—Ponder’s expression of futile rage for shameful dismay. “If you get stuck with any of this compl’cated stuff, my door’s always open. * I am your Archchancellor, after all.”
    “Excuse me, can we tread on ants or not?” said the Senior Wrangler peevishly.
    “If you like.” Ridcully swelled with generosity. “Because, in fact, history already depends on your treading on any ants that you happen to step on. Any ants you tread on, you’ve already trodden on, so if you do it again it’ll be for the first time, because you’re doing it now because you did it then. Which is also now.”
    “Really?”
    “Yes indeed.”
    “So we should have worn bigger boots?” said the Bursar.
    “Try to keep up, Bursar.”
    Ridcully stretched and yawned. “Well, that seems to be it,” he said. “Let’s try to get back to sleep, shall we? It’s been rather a long day.”

    Someone was keeping up.
    After the wizards got back to sleep, a faint light, like burning marsh gas, circled over them.
    He was an omnipresent god, although only in a small area. And he was omnicognizant, but just enough to know that while he did indeed know everything it wasn’t the whole Everything, just the part of it that applied to his island.
    Damn! He’d told himself the cigarette tree would cause trouble. He should have stopped it the moment it started growing. He’d never meant it to get out of hand like this.
    Of course, it had been a shame about the other…pointy creature, but it hadn’t been his fault, had it? Everything had to eat. Some of the things that were turning up on the