'Enjoy,' said the Dean. 'Sensible survival strategy,' said Ridcully. 'Up to a point.' Ponder rolled his eyes. These things always sounded fine when he worked them out in his head. He'd read some of the old books, and sit and think for ages, and a little theory would put itself together in his head in a row of little shiny blocks, and then when he let it out it'd run straight into the Faculty and one of them, one of them, would always ask some bloody stupid question which he couldn't quite answer at the moment. How could you ever make any progress against minds like that? If some god somewhere had said, 'Let there be light,' they'd be the ones to say things like 'Why? The darkness has always been good enough for us.' Old men, that was the trouble. Ponder was not totally enthusiastic about the old traditions, because he was well into his twenties and in a moderately important position and therefore, to some of the mere striplings in the University, a target. Or would have been, if they weren't getting that boiled eyeball feeling by sitting up all night tinkering with Hex. He wasn't interested in promotion, anyway. He'd just be happy if people listened for five minutes, instead of saying, 'Well done, Mister Stibbons, but we tried that once and it doesn't

work,' or, 'We probably haven't got the funding,' or, worst of all, 'You don't get proper fill-in- nouns these days – remember old “nickname” ancient-wizard-who-died-fifty-years-ago-who- Ponder-wouldn't-possibly-be-able-to-remember? Now there was a chap who knew his fill-in- nouns.' Above Ponder, he felt, were a lot of dead men's shoes. And they had living men's feet in them, and were stamping down hard. They never bothered to learn anything, they never bothered to remember anything apart from how much better things used to be, they bickered like a lot of children and the only one who ever said anything sensible said it in orang-utan. He prodded the fire viciously. The wizards had made Mrs Whitlow a polite crude hut out of branches and big woven leaves. She bade them goodnight and demurely pulled some leaves across the entrance behind her. 'A very respectable lady, Mrs Whitlow,' said Ridcully. 'I think I'll turn in myself, too.' There were already one or two sets of snores building up around the fire. 'I think someone ought to stand guard,' said Ponder. 'Good man,' muttered Ridcully, turning over. Ponder gritted his teeth and turned to the Librarian, who was temporarily back in the land of the bipedal and was sitting gloomily wrapped in a blanket. 'At least I expect this is a home from home for you, eh, sir?' The Librarian shook his head. 'Would you be interested in hearing what else is odd about this place?' said Ponder. 'Ook?'

'The driftwood. No one listens to me, but it's important. We must have dragged loads of stuff for the fire, and it's all natural timber, do you notice that? No bits of plank, no old crates, no tatty old sandals. Just . . . ordinary wood.'

'Ook?'

'That means we must be a long way off the normal shipping . . . oh, no . . . don't . . .' The Librarian wrinkled his nose desperately. 'Quickly! Concentrate on having arms and legs! I mean living ones!' The Librarian nodded miserably, and sneezed.

'Awk?' he said, when his shape had settled down again. 'Well,' said Ponder sadly. 'At least you're animate. Possibly rather large for a penguin, though. I think it's your body's survival strategy. It keeps trying to find a stable shape that works.'

'Awk?'

'Funny it can't seem to do anything about the red hair . . .' The Librarian glared at him, shuffled a little way along the beach, and sagged into a heap. Ponder looked around the fire. He seemed to be the man on watch, if only because no one else intended to do it. Well, wasn't that a surprise. Things twittered in the trees. Phosphorescence glimmered on the sea. The stars were coming out. He looked up at the stars. At least you could depend— And, suddenly, he saw what else was wrong. 'Archchancellor!' So how long have you been mad? No, not a good start, really . . . It was quite hard to know how to open the conversation. 'So . . . I didn't expect dwarfs here,' Rincewind said. 'Oh, the family blew in from NoThingfjord when I was a kid,' said Mad. 'Meant to go down the coast a bit, storm got up, next thing we're shipwrecked and up to our knees in parrots. Best thing that could've happened. Back there I'd be down some freezing cold mine picking bits of rock out of the walls but, over here, a dwarf can stand tall.'

'Really,' said Rincewind, his face carefully blank. 'But not too bloody tall!' Mad went on. 'Certainly not.'

'So we settled down, and now my dad's got a chain of bakeries in Bugarup.'

'Dwarf bread?' said Rincewind. 'Too right! That's what kept us going across thousands of miles of shark-infested ocean,' said Mad. 'If we hadn't had that sack of dwarf bread we'd—'

'—never have been able to club the sharks to death?' said Rincewind.

'Ah, you're a man who knows your breads.'

'Big place, Bugarup? Has it got a harbour?'

'People say so. Never been back there. I like the outdoor life.' The ground trembled. The trees by the track shook, even though there was no wind. 'Sounds like a storm,' said Rincewind. 'What's one of them?'

'You know,' said Rincewind. 'Rain.'

'Aw, strain the flaming cows, you don't believe all that stuff, do you? My granddad used to go on about that when he'd been at the beer. It's just an old story. Water falling out of the sky? Do me a favour!'

'It never does that here?'

'Course not!'

'Happens quite a lot where I come from,' said Rincewind. 'Yeah? How's it get up into the sky, then? Water's heavy.'

'Oh, it . . . it . . . I think the sun sucks it up. Or something.'

'How?'

'I don't know. It just happens.'

'And then it drops out of the sky?'

'Yes!'

'For free?'

'Haven't you ever seen rain?'

'Look, everyone knows all the water's deep underground. That's only sense. It's heavy stuff, it leaks down. I never seen it floating around in the air, mate.'

'Well, how do you think it got on the ground in the first place?' Mad looked astonished. 'How do mountains get on the ground?' he said. 'What? They're just there!'

'Oh, so they don't drop out of the sky?'

'Of course not! They're much heavier than air!'

'And water isn't? I've got a coupla drums of it under the cart and you'd sweat to lift 'em.'

'Aren't there any rivers here?'

'Course we've got rivers! This country's got everything, mate!'

'Well, how do you think the water gets into them?' Mad looked genuinely puzzled. 'What'd we want water in the rivers for? What'd it do?'

'Flow out to sea—'

'Bloody waste! That's what you let it do where you come from, is it?'

'You don't let it, it . . . happens . . . it's what rivers do!' Mad gave Rincewind a long hard look. 'Yep. And they call me mad,' he said. Rincewind gave up. There wasn't a cloud in the sky. But the ground shook again. Archchancellor Ridcully glared at the sky as if it was doing this to upset him personally. 'What, not one?' he said. Technically, not a single familiar constellation,' said the Chair of Indefinite Studies frantically. 'We've counted three thousand, one hundred and ninety-one constellations that could be called the Triangle, for example, but the Dean says some of them don't count because they use the same stars—' There's not a single star I recognize,' said the Senior Wrangler. Ridcully waved his hands in the air. They change a bit all the time,' he said. The Turtle swims through space and—'

'Not this fast!' said the Dean. The dishevelled wizards looked up at the rapidly crowding night. Discworld constellations changed frequently as the world moved through the void, which meant that astrology was cutting-edge research rather than, as elsewhere, a clever way of avoiding a proper job. It was amazing how human traits and affairs could so reliably and continuously be guided by a succession of big balls of plasma billions of miles away, most of whom have never even heard of humanity. 'We're marooned on some other world!' moaned the Senior Wrangler.

'Er . . . I don't think so,' said Ponder. 'You've got a better suggestion, I suppose?'

'Er . . . you see that big patch of stars over there?' The wizards looked at the large cluster twinkling near the horizon. 'Very pretty,' said Ridcully. 'Well?'

'I think it's what we call the Small Boring Group of Faint Stars. It's about the right shape,' said Ponder. 'And I know what you're going to say, sir, you're going to say, “But they're just a blob in the sky, not a patch on the blobs we used to get,” sir, but, you see, that's what they might have looked like when Great A'Tuin was much closer to them, thousands of years ago. In other words, sir,' Ponder drew a deep breath, in dread of everything that was to come, 'I think we've travelled backwards in time. For thousands of years.' And that was the other side of the odd thing about wizards. While they were quite capable of spending half an hour arguing that it could not possibly be Tuesday, they'd take the outrageous in their pointy-shoed stride. The Senior Wrangler even looked relieved. 'Oh, is that it?' he said. 'Bound to happen eventually,' said the Dean. 'It's not written down anywhere that these holes connect to the same time, after all.'

'Going to make gettin' back a bit tricky,' said Ridcully. 'Er . . .' Ponder began. 'It might not be so simple as that, Archchancellor.'

'You mean as simple as finding a way to move through time and space?'

'I mean there might not be any there to go back to,' said Ponder. He shut his eyes. This was going to be difficult, he knew it. 'Of course there is,' said Ridcully. 'We were there only this morn— Only yesterday. That is to say, yesterday thousands of years in the future, naturally.'

'But if we're not careful we might alter the future, you see,' said Ponder. The mere presence of us in the past might alter the future. We might already have altered history. It's vital that I tell you this.'

'He's got a point, Ridcully,' said the Dean. 'Was there any of that rum left, by the way?'

'Well, there isn't any history happening here,' said Ridcully. 'It's just an odd little island.'

'I'm afraid tiny actions anywhere in the world may have huge ramifications, sir,' said Ponder. 'We certainly don't want any ramifications. Well, what's your point? What do you advise?'

It had been going so well. They almost seemed up to speed. This may have been what caused Ponder to act like the man who, having so far fallen a hundred feet without any harm, believes that the last few inches to the ground will be a mere formality. 'To use the classic metaphor, the important thing is not to kill your own grandfather,' he said, and smacked into the bedrock. 'What the hell would I want to do that for?' said Ridcully. 'I quite liked the old boy.'

'No, of course, I mean accidentally,' said Ponder. 'But in any case—'

'Really? Well, as you know, I accidentally kill people every day,' said Ridcully. 'Anyway, I don't see him around—'

'It's just an illustration, sir. The problem is cause and effect, and the point is—' The point, Mister Stibbons, is that you suddenly seem to think everyone comes over all fratricidal when they go back in time. Now, if I'd met my grandfather I'd buy him a drink and tell him not to assume that snakes won't bite if you shout at them in a loud voice, information which he might come to thank me for in later life.'

'Why?' said Ponder. 'Because he would have some later life,' said Ridcully. 'No, sir, no! That'd be worse than shooting him!'

'It would?'

'Yes, sir!'

'I think there may be one or two steps in your logic that I have failed to grasp, Mister Stibbons,' said the Archchancellor coldly. 'I suppose you're not intending to shoot your own grandfather, by any chance?'

'Of course not!' snapped Ponder. 'I don't even know what he looked like. He died before I was born.'