Magrat listened to all this with interest. Her own preparations had consisted of a large sack containing several changes of clothes to accommodate whatever weather foreign parts might suffer from, and a rather smaller one containing a number of useful-looking books from Desiderata Hollow's cottage. Desiderata had been a great note-taker, and had filled dozens of little books with neat writing and chapter headings like 'With Wand and Broomstick Across the Great Nef Desert'.

What she had never bothered to do, it seemed, was write down any instructions for the wand. As far as Magrat knew, you waved it and wished.

Along the track to her cottage, several unanticipated pumpkins bore witness to this as an unreliable strategy. One of them still thought it was a stoat.

Now Magrat was left alone with Jason, who shuffled his feet.

He touched his forelock. He'd been brought up to be

respectful to women, and Magrat fell broadly into this category.

'You will look after our mum, won't you, Mistress Garlick?' he said, a hint of worry in his voice. 'She'm acting awful strange.'

Magrat patted him gently on the shoulder.

'This sort of thing happens all the time,' she said. 'You know, after a woman's raised a family and so on, she wants to start living her own life.'

'Whose life she bin living, then?'

Magrat gave him a puzzled look. She hadn't questioned the wisdom of the thought when it had first arrived in her head.

'You see, what it is,' she said, making an explanation up as she went along, 'there comes a time in a woman's life when she wants to find herself.'

'Why dint she start looking here?' said Jason plaintively. 'I mean, I ain't wanting to talk out of turn, Miss Garlick, but we was looking to you to persuade her and Mistress Weatherwax not to go.'

'I tried,' said Magrat. 'I really did. I said, you don't want to go, I said. Anno domini, I said. Not as young as you used to be, I said. Silly to go hundreds of miles just for something like this, especially at your age.'

Jason put his head on one side. Jason Ogg wouldn't end up in the finals of the All-Discworld uptake speed trials, but he knew his own mother.

'You said all that to our mum?' he said.

'Look, don't worry,' said Magrat, 'I'm sure no harm can- '

There was a crash somewhere over their heads. A few autumn leaves spiralled gently towards the ground.

'Bloody tree . . . who put that bloody tree there?' came a voice from on high.

'That'll be Granny,' said Magrat.

It was one of the weak spots of Granny Weatherwax's otherwise well-developed character that she'd never bothered to get the hang of steering things. It was alien to her nature. She took the view that it was her job to move and the rest of the world to arrange itself so that she arrived at her destination. This meant that she occasionally had to climb down trees she'd never climbed up. This she did now, dropping the last few feet and daring anyone to comment.

'Well, now we're all here,' said Magrat brightly.

It didn't work. Granny Weatherwax's eyes focused immediately somewhere around Magrat's knees.

'And what do you think you're wearing?' she said.

'Ah. Um. I thought ... I mean, it gets cold up there . . . what with the wind and everything,' Magrat began. She had been dreading this, and hating herself for being so weak. After all, they were practical. The idea had come to her one night. Apart from anything else, it was almost impossible to do Air Lobsang Dibbler's cosmic harmony death kicks when your legs kept getting tangled in a skirt.

'Trousers?'

'They're not exactly the same as ordinary - '

'And there's men 'ere lookin',' said Granny. 'I think it's shameful!'

'What is?' said Nanny Ogg, coming up behind her.

'Magrat Garlick, standin' there bifurcated,' said Granny, sticking her nose in the air.

'Just so long as she got the young man's name and address,' said Nanny Ogg amiably.

'Nanny!' said Magrat.

'I think they look quite comfy,' Nanny went on. 'A bit baggy, though.'

'I don't 'old with it,' said Granny. 'Everyone can see her legs.'

'No they can't,' said Nanny. 'The reason being, the material is in the way.'

'Yes, but they can see where her legs are,' said Granny Weatherwax.

'That's silly. That's like saying everyone's naked under their clothes,' said Magrat.

'Magrat Garlick, may you be forgiven,' said Granny Weatherwax.

'Well, it's true!'

'I'm not,' said Granny flatly, 'I got three vests on.'

She looked Nanny up and down; Gytha Ogg, too, had made sartorial preparations for foreign parts. Granny Weatherwax could find little to disapprove of, although she made an effort.

'And will you look at your hat,' she mumbled. Nanny, who had known Esme Weatherwax for seventy years, merely grinned.

'All the go, ain't it?' she said. 'Made by Mr Vernissage over in Slice. It's got willow reinforcing all the way up to the point and eighteen pockets inside. Can stop a blow with a hammer, this hat. And how about these?'

Nanny raised the hem of her skirt. She was wearing new boots. As boots, Granny Weatherwax could find nothing to complain of in them. They were of proper witch construction, which is to say that a loaded cart could have run over them without causing a dent in the dense leather. As boots, the only thing wrong with them was the colour.

'Red?' said Granny. 'That's no colour for a witch's boots!'

'I likes 'em,' said Nanny.

Granny sniffed. 'You can please yourself, I'm sure,' she said. 'I'm sure in foreign parts they goes in for all sorts of outlandish things. But you know what they say about women who wear red boots.'

'Just so long as they also say they've got dry feet,' said Nanny cheerfully. She put her door key into Jason's hand.

'I'll write you letters if you promise to find someone to read them to you,' she said.

'Yes, mum. What about the cat, mum?' said Jason.

'Oh, Greebo's coming with us,' said Nanny Ogg.

'What? But he's a cat!' snapped Granny Weatherwax. 'You can't take cats with you! I'm not going travellin' with no cat! It's bad enough travellin' with trousers and provocative boots!'

'He'll miss his mummy if he's left behind, won't he,' crooned Nanny Ogg, picking up Greebo. He hung limply, like a bag of water gripped around the middle.

To Nanny Ogg Greebo was still the cute little kitten that chased balls of wool around the floor.

To the rest of the world he was an enormous tomcat, a parcel of incredibly indestructible life forces in a skin that looked less like a fur than a piece of bread that had been left in a damp place for a fortnight. Strangers often took pity on him because his ears were non-existent and his face looked as though a bear had camped on it. They could not know that this was because Greebo, as a matter of feline pride, would attempt to fight or rape absolutely anything, up to and including a four-horse logging wagon. Ferocious dogs would whine and hide under the stairs when Greebo sauntered down the street. Foxes kept away from the village. Wolves made a detour.

'He's an old softy really,' said Nanny.

Greebo turned upon Granny Weatherwax a yellow-eyed stare of self-satisfied malevolence, such as cats always reserve for people who don't like them, and purred. Greebo was possibly the only cat who could snigger in purr.

'Anyway,' said Nanny, 'witches are supposed to like cats.'

'Not cats like him, they're not.'

'You're just not a cat person, Esme,' said Nanny, cuddling Greebo tightly.

Jason Ogg pulled Magrat aside.

'Our Scan read to me in the almanac where there's all these fearsome wild beasts in foreign parts,' he whispered.

'Huge hairy things that leap out on travellers, it said. I'd hate to think what'd happen if they leapt out on mum and Granny.'

Magrat looked up into his big red face.

'You will see no harm comes to them, won't you,' said Jason.

'Don't you worry,' she said, hoping that he needn't. 'I'll do my best.'

Jason nodded. 'Only it said in the almanac that some of them were nearly extinct anyway,' he said.

The sun was well up when the three witches spiralled into the sky. They had been delayed for a while because of the intractability of Granny Weatherwax's broomstick, the starting of which always required a great deal of galloping up and down. It never seemed to get the message until it was being shoved through the air at a frantic running speed. Dwarf engineers everywhere had confessed themselves totally mystified by it. They had replaced the stick and the bristles dozens of times.

When it rose, eventually, it was to a chorus of cheers.

The tiny kingdom of Lancre occupied little more than a wide ledge cut into the side of the Ramtop mountains. Behind it, knife-edge peaks and dark winding valleys climbed into the massive backbone of the central ranges.

In front, the land dropped abruptly to the Sto plains, a blue haze of woodlands, a broader expanse of ocean and, somewhere in the middle of it all, a brown smudge known as Ankh-Morpork.

A skylark sang, or at least started to sing. The rising point of Granny Weatherwax's hat right underneath it completely put it off the rhythm.

'I ain't going any higher,' she said.

'If we go high enough we might be able to see where we're going,' said Magrat.

'You said you looked at Desiderata's maps,' said Granny.

'It looks different from up here, though,' said Magrat. 'More . . . sticking up. But I think we go ... that way.'

'You sure?'

Which was the wrong question to ask a witch. Especially if the person doing the asking was Granny Weatherwax.

'Positive,' said Magrat.

Nanny Ogg looked up at the high peaks.

'There's a lot of big mountains that way,' she said.

They rose tier on tier, speckled with snow, trailing endless pennants of ice crystals high overhead. No-one ski'd in the high Ramtops, at least for more than a few feet and a disappearing scream. No-one ran up them wearing dirndls and singing. They were not nice mountains. They were the kind of mountains where winters went for their summer holidays.

"There's passes and things through them,' said Magrat uncertainly.

'Bound to be,' said Nanny.

You can use two mirrors like this, if you know the way of it: you set them so that they reflect each other. For if images can steal a bit of you, then images of images can amplify you, feeding you back on yourself, giving you power. . .

And your image extends forever, in reflections of reflections of reflections, and every image is the same, all the way around the curve of light.

Except that it isn't.

Mirrors contain infinity.

Infinity contains more things than you think.

Everything, for a start.

Including hunger.

Because there's a million billion images and only one soul to go around.

Mirrors give plenty, but they take away lots.

Mountains unfolded to reveal more mountains. Clouds gathered, heavy and grey.

'I'm sure we're going the right way,' said Magrat. Freezing rock stretched away. The witches flew along a maze of twisty little canyons, all alike.

'Yeah,' said Granny.

'Well, you won't let me fly high enough,' said Magrat.

'It's going to snow like blazes in a minute,' said Nanny Ogg.

It was early evening. Light was draining out of the high valleys like custard.

'I thought . . . there'd be villages and things,' said Magrat, 'where we could buy interesting native produce and seek shelter in rude huts.'

'You wouldn't even get trolls up here,' said Granny.

The three broomsticks glided down into a bare valley, a mere notch in the mountain side.

'And it's bloody cold,' said Nanny Ogg. She grinned. 'Why're they called rude huts, anyway?'

Granny Weatherwax climbed off her broomstick and looked at the rocks around her. She picked up a stone and sniffed it. She wandered over to a heap of scree that looked like any other heap of scree to Magrat, and prodded it.