'You're staying here, sir?' Death looked up and down the street. His eye-sockets flared.

I THOUGHT I MIGHT STROLL AROUND A BIT, he said mysteriously. I DON'T SEEM TO FEEL QUITE RIGHT. I COULD DO WITH THE FRESH AIR. He seemed to remember something, reached into the mysterious shadows of his cloak, and pulled out three hourglasses. ALL STRAIGHTFORWARD, he said. ENJOY YOURSELF.

He turned and strode off down the street, humming.

'Um. Thank you,' said Mort. He held the hourglasses up to the light, noting the one that was on its very last few grains of sand.

'Does this mean I'm in charge?' he called, but Death had turned the corner.

Binky greeted him with a faint whinny of recognition. Mort mounted up, his heart pounding with apprehension and responsibility. His fingers worked automatically, taking the scythe out of its sheath and adjusting and locking the blade (which flashed steely blue in the night, slicing the starlight like salami). He mounted carefully, wincing at the stab from his saddlesores, but Binky was like riding a pillow. As an afterthought, drunk with delegated authority, he pulled Death's riding cloak out of its saddlebag and fastened it by its silver brooch.

He took another look at the first hourglass, and nudged Binky with his knees. The horse sniffed the chilly air, and began to trot.

Behind them Cutwell burst out of his doorway, accelerating down the frosty street with his robes flying out behind him.

Now the horse was cantering, widening the distance between its hooves and the cobbles. With a swish of its tail it cleared the housetops and floated up into the chilly sky.

Cutwell ignored it. He had more pressing things on his mind. He took a flying leap and landed full length in the freezing waters of the horsetrough, lying back gratefully among the bobbing ice splinters. After a while the water began to steam. Mort kept low for the sheer exhilaration of the speed. The sleeping countryside roared soundlessly underneath. Binky moved at an easy gallop, his great muscles sliding under his skin as easily as alligators off a sandbank, his mane whipping in Mort's face. The night swirled away from the speeding edge of the scythe, cut into two curling halves.

They sped under the moonlight as silent as a shadow, visible only to cats and people who dabbled in things men were not meant to wot of.

Mort couldn't remember afterwards, but very probably he laughed.

Soon the frosty plains gave way to the broken lands around the mountains, and then the marching ranks of the Ramtops themselves raced across the world towards them. Binky put his head down and opened his stride, aiming for a pass between two mountains as sharp as goblins' teeth in the silver light. Somewhere a wolf howled.

Mort took another look at the hourglass. Its frame was carved with oak leaves and mandrake roots, and the sand inside, even by moonlight, was pale gold. By turning the glass this way and that, he could just make out the name 'Ammeline Hamstring' etched in the faintest of lines.

Binky slowed to a canter. Mort looked down at the roof of a forest, dusted with snow that was either early or very, very late; it could have been either, because the Ramtops hoarded their weather and doled it out with no real reference to the time of year.

A gap opened up beneath them. Binky slowed again, wheeled around and descended towards a clearing that was white with drifted snow. It was circular, with a tiny cottage in the exact middle. If the ground around it hadn't been covered in snow, Mort would have noticed that there were no tree stumps to be seen; the trees hadn't been cut down in the circle, they'd simply been discouraged from growing there. Or had moved away.

Candlelight spilled from one downstairs window, making a pale orange pool on the snow.

Binky touched down smoothly and trotted across the freezing crust without sinking. He left no hoofprints, of course.

Mort dismounted and walked towards the door, muttering to himself and making experimental sweeps with the scythe.

The cottage roof had been built with wide eaves, to shed snow and cover the logpile. No dweller in the high Ramtops would dream of starting a winter without a logpile on three sides of the house. But there wasn't a logpile here, even though spring was still a long way off.

There was, however, a bundle of hay in a net by the door. It had a note attached, written in big, slightly shaky capitals: FOR THEE HORS.

It would have worried Mort if he'd let it. Someone was expecting him. He'd learned in recent days, though, that rather than drown in uncertainty it was best to surf right over the top of it. Anyway, Binky wasn't worried by moral scruples and bit straight in.

It did leave the problem of whether to knock. Somehow, it didn't seem appropriate. Supposing no-one answered, or told him to go away?

So he lifted the thumb latch and pushed at the door. It swung inwards quite easily, without a creak.

There was a low-ceilinged kitchen, its beams at trepanning height for Mort. The light from the solitary candle glinted off crockery on a long dresser and flagstones that had been scrubbed and polished into iridescence. The fire in the cave-like inglenook didn't add much light, because it was no more than a heap of white ash under the remains of a log. Mort knew, without being told, that it was the last log.

An elderly lady was sitting at the kitchen table, writing furiously with her hooked nose only a few inches from the paper. A grey cat curled on the table beside her blinked calmly at Mort.

The scythe bumped off a beam. The woman looked up.

'Be with you in a minute,' she said. She frowned at the paper. 'I haven't put in the bit about being of sound mind and body yet, lot of foolishness anyway, no-one sound in mind and body would be dead. Would you like a drink?'

'Pardon?' said Mort. He recalled himself, and repeated 'PARDON?'

'If you drink, that is. It's raspberry port. On the dresser. You might as well finish the bottle.'

Mort eyed the dresser suspiciously. He felt he'd rather lost the initiative. He pulled out the hourglass and glared at it. There was a little heap of sand left.

There's still a few minutes yet,' said the witch, without looking up.

'How, I mean, HOW DO YOU KNOW?'

She ignored him, and dried the ink in front of the candle, sealed the letter with a drip of wax, and tucked it under the candlestick. Then she picked up the cat.

'Granny Beedle will be around directly tomorrow to tidy up and you're to go with her, understand? And see she lets Gammer Nutley have the pink marble washstand, she's had her eye on it for years.'

The cat yawped knowingly.

'I haven't, that is, I HAVEN'T GOT ALL NIGHT, YOU KNOW,' said Mort reproachfully.

'You have, I haven't, and there's no need to shout,' said the witch. She slid off her stall and then Mort saw how bent she was, like a bow. With some difficulty she unhooked a tall pointed hat from its nail on the wall, skewered it into place on her white hair with a battery of hatpins, and grasped two walking sticks.

She tottered across the floor towards Mort, and looked up at him with eyes as small and bright as blackcurrants.

'Will I need my shawl? Shall I need a shawl, d'you think? No, I suppose not. I imagine it's quite warm where I'm going.' She peered closely at Mort, and frowned.

'You're rather younger than I imagined,' she said. Mort said nothing. Then Goodie Hamstring said, quietly, 'You know, I don't think you're who I was expecting at all.'

Mort cleared his throat.

'Who were you expecting, precisely?' he said.

'Death,' said the witch, simply. 'It's part of the arrangement, you see. One gets to know the time of one's death in advance, and one is guaranteed – personal attention.'

'I'm it,'said Mort.

'It?'

'The personal attention. He sent me. I work for him. No-one else would have me.' Mort paused. This was all wrong. He'd be sent home again in disgrace. His first bit of responsibility, and he'd ruined it. He could already hear people laughing at him.

The wail started in the depths of his embarrassment and blared out like a foghorn. 'Only this is my first real job and it's all gone wrong!'

The scythe fell to the floor with a clatter, slicing a piece off the table leg and cutting a flagstone in half.

Goodie watched him for some time, with her head on one side. Then she said, 'I see. What is your name, young man?'

'Mort,' sniffed Mort. 'Short for Mortimer.'

'Well, Mort, I expect you've got an hourglass somewhere about your person,'

Mort nodded vaguely. He reached down to his belt and produced the glass. The witch inspected it critically.

'Still a minute or so,' she said. 'We don't have much time to lose. Just give me a moment to lock p.'

'But you don't understand!' Mort wailed. 'I'll mess it all up! I've never done this before!'

She patted his hand. 'Neither have I,' she said. 'We can learn together. Now pick up the scythe and try to act your age, there's a good boy.'

Against his protestations she shooed him out into the snow and followed behind him, pulling the door shut and locking it with a heavy iron key which she hung on a nail by the door.

The frost had tightened its grip on the forest, squeezing it until the roots creaked. The moon was setting, but the sky was full of hard white stars that made the winter seem colder still. Goodie Hamstring shivered.

'There's an old log over there,' she said conversationally. 'There's quite a good view across the valley. In the summertime, of course. I should like to sit down.'

Mort helped her through the drifts and brushed as much snow as possible off the wood. They sat down with the hourglass between them. Whatever the view might have been in the summer, it now consisted of black rocks against a sky from which little flakes of snow were now tumbling.

'I can't believe all this,' said Mort. 'I mean you sound as if you want to die.'

'There's some things I shall miss,' she said. 'But it gets thin, you know. Life, I'm referring to. You can't trust your own body any more, and it's time to move on. I reckon it's about time I tried something else. Did he tell you magical folk can see him all the time?'

'No,' said Mort, inaccurately.

'Well, we can.'

'He doesn't like wizards and witches much,' Mort volunteered.

'Nobody likes a smartass,' she said with some satisfaction. 'We give him trouble, you see. Priests don't, so he likes priests.'

'He's never said,' said Mort.

'Ah. They're always telling folk how much better it's going to be when they're dead. We tell them it could be pretty good right here if only they'd put their minds to it.'

Mort hesitated. He wanted to say: you're wrong, he's not like that at all, he doesn't care if people are good or bad so long as they're punctual. And kind to cats, he added.

But he thought better of it. It occurred to him that people needed to believe things.

The wolf howled again, so near that Mort looked around apprehensively. Another one across the valley answered it. The chorus was picked up by a couple of others in the depths of the forest. Mort had never heard anything so mournful.

He glanced sideways at the still figure of Goodie Hamstring and then, with mounting panic, at the hourglass. He sprang to his feet, snatched up the scythe, and brought it around in a two-handed swing.

The witch stood up, leaving her body behind.

'Well done,' she said. 'I thought you'd missed it, for a minute, there.'

Mort leaned against a tree, panting heavily, and watched Goodie walk around the log to look at herself.

'Hmm,' she said critically. Time has got a lot to answer for.' She raised her hand and laughed to see the stars through it.

Then she changed. Mort had seen this happen before, when the soul realised it was no longer bound by the body's morphic field, but never under such control. Her hair unwound itself from its tight bun, changing colour and lengthening. Her body straightened up. Wrinkles dwindled and vanished. Her grey woollen dress moved like the surface of the sea and ended up tracing entirely different and disturbing contours.