There was a rock a little way away. But there were rocks everywhere, the very bones of the Disc were near he surface here.

He looked hard at the yew tree, just in case it had been speaking. But the yew, being a fairly solitary tree, hadn't heard about Rincewind the arborial saviour, and in any case was asleep.

'If that was you, Twoflower, I knew it was you all along,' said Rincewind. His voice sounded suddenly clear and very alone in the gathering dusk.

Rincewind remembered the only fact he knew for sure about trolls, which was that they turned to stone when exposed to sunlight, so that anyone who employed trolls to work during daylight had to spend a fortune in barrier cream.

But now that he came to think about it, it didn't say anywhere what happened to them after the sun had gone down again . . .

The last of the daylight trickled out of the landscape. And there suddenly seemed to be a great many rocks about.

'He's an awful long time with those onions,' said Two-flower. 'Do you think we'd better go and look for him?'

'Wishards know how to look after themshelves,' said Cohen. 'Don't worry.' He winced. Bethan was cutting his toenails.

'He's not a terribly good wizard, actually,' said Twoflower, drawing nearer the fire. 'I wouldn't say this to his face, but' – he leaned towards Cohen – 'I've never actually seen him do any magic.'

'Right, let's have the other one,' said Bethan.

'Thish is very kind of you.'

'You'd have quite nice feet if only you'd look after them.'

'Can't sheem to bend down like I used to,' said Cohen, sheepishly. 'Of courshe, you don't get to meet many chiropodishts in my line of work. Funny, really. I've met any amount of snake prieshts, mad godsh, warlordsh, never any chiropodishts. I shupposhe it wouldn't look right, really – Cohen Against the Chiropodishts . . .'

'Or Cohen And The Chiropractors of Doom,' suggested Bethan. Cohen cackled.

'Or Cohen And The Mad Dentists!' laughed Twoflower.

Cohen's mouth snapped shut.

'What'sh sho funny about that?' he asked, and his voice had knuckles in it.

'Oh, er, well,' said Twoflower. Tour teeth, you see . . .'

'What about them?' snapped Cohen.

Twoflower swallowed. 'I can't help noticing that they're, um, not in the same geographical location as your mouth.'

Cohen glared at him. Then he sagged, and looked very small and old.

'True, of corsh,' he muttered. 'I don't blame you. It'sh hard to be a hero with no teethsh. It don't matter what elsh you loosh, you can get by with one eye even, but you show 'em a mouth full of gumsh and no-one hash any reshpect.'

'I do,' said Bethan loyally.

'Why don't you get some more?'said Twoflower brightly.

'Yesh, well, if I wash a shark or something, yesh, I'd grow shome,' said Cohen sarcastically.

'Oh, no, you buy them,' said Twoflower. 'Look, I'll show you – er, Bethan, do you mind looking the other way?' He waited until she had turned around and then put his hand to his mouth.

'You shee?' he said.

Bethan heard Cohen gasp.

'You can take yoursh out?'

'Oh yesh. I've got sheveral shets. Excushe me—' there was a swallowing noise, and then in a more normal voice Twoflower said, 'It's very convenient, of course.'

Cohen's very voice radiated awe, or as much awe as is possible without teeth, which is about the same amount as with teeth but sounds a great deal less impressive.

'I should think show,' he said. 'When they ache, you jusht take them out and let them get on with it, yesh?

Teach the little buggersh a lesshon, shee how they like being left to ache all by themshelvesh!'

That's not quite right,' said Twoflower carefully. They're not mine, they just belong to me.'

'You put shomeone elshe's teethsh in your mouth?'

'No, someone made them, lots of people wear them where I come from, it's a—'

But Twoflower's lecture on dental appliances went ungiven, because somebody hit him.

The Disc's little moon toiled across the sky. It shone by its own light, owing to the cramped and rather inefficient astronomical arrangements made by the Creator, and was quite crowded with assorted lunar goddesses who were not, at this particular time, paying much attention to what went on in the Disc but were getting up a petition about the Ice Giants.

Had they looked down, they would have seen Rincewind talking urgently to a bunch of rocks.

Trolls are one of the oldest lifeforms in the multiverse, dating from an early attempt to get the whole life thing on the road without all that squashy protoplasm. Individual trolls live for a long time, hibernating during the summertime and sleeping during the day, since heat affects them and makes them slow. They have a fascinating geology. One could talk about tribology, one could mention the semiconductor effects of impure silicon, one could talk about the giant trolls of prehistory who make up most of the Disc's major mountain ranges and will cause some real problems if they ever awake, but the plain fact is that without the Disc's powerful and pervasive magical field trolls would have died out a long time ago.

Psychiatry hadn't been invented on the Disc. No-one had ever shoved an inkblot under Rincewind's nose to see if he had any loose toys in the attic. So the only way he'd have been able to describe the rocks turning back into rolls was by gabbling vaguely about how pictures suddenly form when you look at the fire, or clouds.

One minute there'd be a perfectly ordinary rock, and suddenly a few cracks that had been there all along took on the definite appearance of a mouth or a pointed ear. A moment later, and without anything actually changing at all, a troll would be sitting there, grinning at him with a mouth full of diamonds.

They wouldn't be able to digest me, he told himself. I'd make them awfully ill.

It wasn't much of a comfort.

'So you're Rincewind the wizard,' said the nearest one. It sounded like someone running over gravel. 'I dunno. I thought you'd be taller.'

'Perhaps he's eroded a bit,' said another one. 'The legend is awfully old.'

Rincewind shifted awkwardly. He was pretty certain the rock he was sitting on was changing shape, and a tiny troll – hardly any more than a pebble – was sitting companionably on his foot and watching him with extreme interest.

'Legend?' he said. 'What legend?'

'It's been handed down from mountain to gravel since the sunset[3] of time,' said the first troll. ' “When the red star lights the sky Rincewind the wizard will come looking for onions. Do not bite him. It is very important that you help him stay alive.” '

There was a pause.

'That's it?' said Rincewind.

'Yes,' said the troll. 'We've always been puzzled about it. Most of our legends are much more exciting. It was more interesting being a rock in the old days.'

'It was?' said Rincewind weakly.

'Oh yes. No end of fun. Volcanoes all over the place. It really meant something, being a rock then.There was none f this sedimentary nonsense, you were igneous or nothing. Of course, that's all gone now. People call themselves trolls today, well, sometimes they're hardly more than slate. Chalk even. I wouldn't give myself airs if you could use me to draw with, would you?'

'No,' said Rincewind quickly. 'Absolutely not, no. This, er, this legend thing. It said you shouldn't bite me?'

'That's right!' said the little troll on his foot, 'and it was me who told you where the onions were!'

'We're rather glad you came along,' said the first troll, which Rincewind couldn't help noticing was the biggest one there. 'We're a bit worried about this new star. What does it mean?'

'I don't know,' said Rincewind. 'Everyone seems to think I know about it, but I don't —'

'It's not that we would mind being melted down,' said the big troll. That's how we all started, anyway. But we thought, maybe, it might mean the end of everything and that doesn't seem a very good thing.'

'It's getting bigger,' said another troll. 'Look at it now. Bigger than last night.'

Rincewind looked. It was definitely bigger than last night.

'So we thought you might have some suggestions?' said the head troll, as meekly as it is possible to sound with a voice like a granite gargle.

'You could jump over the Edge,' said Rincewind. There must be lots of places in the universe that could do with some extra rocks.'

'We've heard about that,' said the troll. 'We've met rocks that tried it. They say you float about for millions of years and then you get very hot and burn away and end up at the bottom of a big hole in the scenery. That doesn't sound very bright.'

It stood up with a noise like coal rattling down a chute, and stretched its thick, knobbly arms.

'Well, we're supposed to help you,' it said. 'Anything you want doing?'

'I was supposed to be making some soup,' said Rincewind. He waved the onions vaguely. It was probably not the most heroic or purposeful gesture ever made.

'Soup?' said the troll. 'Is that all?'

'Well, maybe some biscuits too.'

The trolls looked at one another, exposing enough mouth jewellery to buy a medium-sized city.

Eventually the biggest troll said, 'Soup it is, then.' It shrugged grittily. 'It's just that we imagined that the legend would, well, be a little more – I don't know, somehow I thought – still, I expect it doesn't matter.'

It extended a hand like a bunch of fossil bananas.

'I'm Kwartz,' it said. 'That's Krysoprase over there, and Breccia, and Jasper, and my wife Beryl – she's la bit meta-morphic, but who isn't these days? Jasper, get off his foot.'

Rincewind took the hand gingerly, bracing himself for the crunch of crushed bone. It didn't come. The troll's hand was rough and a bit lichenous around the fingernails.

'I'm sorry,' said Rincewind. 'I never really met trolls before.'

'We're a dying race,' said Kwartz sadly, as the party set off under the stars. 'Young Jasper's the only pebble in our tribe. We suffer from philosophy, you know.'

'Yes?' said Rincewind, trying to keep up. The troll band moved very quickly, but also very quietly, big round shapes moving like wraiths through the night. Only the occasional flat squeak of a night creature who hadn't heard them approaching marked their passage.

'Oh, yes. Martyrs to it. It comes to all of us in the end. One evening, they say, you start to wake up and then you think “Why bother?” and you just don't. See those boulders over there?'

Rincewind saw some huge shapes lying in the grass.

'The one on the end's my aunt. I don't know what's she's thinking about, but she hasn't moved for two hundred years.'

'Gosh, I'm sorry.'

'Oh, it's no problem with us around to look after them,' aid Kwartz. 'Not many humans around here, you see. I know it's not your fault, but you don't seem to be able to spot the difference between a thinking troll and an ordinary rock. My great-uncle was actually quarried, you know.'

'That's terrible!'

'Yes, one minute he was a troll, the next he was an ornamental fireplace.'

They paused in front of a familiar-looking cliff. The scuffed remains of a fire smouldered in the darkness.

'It looks like there's been a fight,' said Beryl.

'They're all gone!' said Rincewind. He ran to the end of the clearing. 'The horses, too! Even the Luggage!'

'One of them's leaked,' said Kwartz, kneeling down. 'That red watery stuff you have in your insides. Look.'

'Blood!'

'Is that what it's called? I've never really seen the point of it.'

Rincewind scuttled about in the manner of one totally at his wits' end, peering behind bushes in case anyone was hiding there. That was why he tripped over a small green bottle.

'Cohen's linament!' he moaned. 'He never goes anywhere without it!'