The interruption was caused by a sudden screaming noise and a flurry of snow and sparks that blew the fire across the dark hut; there was a brief blurred vision and then the opposite wall was blasted aside and the apparition vanished.

There was a long silence. Then a slightly shorter silence. Then the old shaman said carefully, ‘You didn’t just see two men go through upside down on a broomstick, shouting and screaming at each other, did you?’

The boy looked at him levelly. ‘Certainly not,’ he said.

The old man heaved a sigh of relief. Thank goodness for that,’ he said. ‘Neither did I.’

The cottage was in turmoil, because not only did the wizards want to follow the broomstick, they also wanted to prevent each other from doing so, and this led to several regrettable incidents.The most spectacular, and certainly the most tragic, happened when one Seer attempted to use his seven league boots without the proper sequence of spells and preparations. Seven league boots, as has already been intimated, are a tricksy form of magic at best, and he remembered too late that the utmost caution must be taken in using a means of transport which, when all is said and done, relies for its effectiveness on trying to put one foot twenty-one miles in front of the other.

The first snowstorms of winter were raging, and in fact there was a suspiciously heavy covering of cloud over most of the Disc. And yet, from far above and by the silver light of the discworld’s tiny moon, it presented one of the most beautiful sights in the multiverse.

Great streamers of cloud, hundreds of miles along, swirled from the waterfall at the Rim to the mountains of the Hub. In the cold crystal silence the huge white spiral glittered frostily under the stars, imperceptibly turning, very much as though God had stirred His coffee and then poured the cream in.

Nothing disturbed the glowing scene, which —

Something small and distant broke through the cloud layer, trailing shreds of vapour. In the stratospheric calm the sounds of bickering came sharp and clear.

‘You said you could fly one of these things!’

‘No I didn’t; I just said you couldn’t!’

‘But I’ve never been on one before!’

‘What a coincidence!’

‘Anyway, you said– look at the sky!’

‘No I didn’t!’

‘What’s happened to the stars?’

And so it was that Rincewind and Twoflower became the first two people on the Disc to see what the future held.

A thousand miles behind them the Hub mountain of Cori Celesti stabbed the sky and cast a knife-bright shadow across the broiling clouds, so that Gods ought to have noticed too—but the Gods don’t normally look at the sky and in any case were engaged in litigation with the Ice Giants, who had refused to turn their radio down.

Rimwards, in the direction of Great A’Tuin’s travel, the sky had been swept of stars.

In that circle of blackness there was just one star, a red and baleful star, a star like the glitter in the eyesocket of a rabid mink. It was small and horrible and uncompromising. And the Disc was being carried straight towards it.

Rincewind knew precisely what to do in these circumstances. He screamed and pointed the broomstick straight down.

Galder Weatherwax stood in the centre of the octogram and raised his hands.

‘Urshalo, dileptor, c’hula, do my bidding!’

A small mist formed over his head. He glanced sideways at Trymon, who was sulking at the edge of the magic circle.

‘This next bit’s quite impressive,’ he said. ‘Watch. Kot-b’hai! Kot-sham! To me, o spirits of small isolated rocks and worried mice not less than three inches long!’

‘What?’ said Trymon.

That bit took quite a lot of research,’ agreed Galder, especially the mice. Anyway, where was I? Oh, yes...’

He raised his arms again. Trymon watched him, and licked his lips distractedly. The old fool was really concentrating, bending his mind entirely to the Spell and hardly paying any attention to Trymon.

Words of power rolled around the room, bouncing off the walls and scuttling out of sight behind shelves and jars. Trymon hesitated.

Galder shut his eyes momentarily, his face a mask of ecstacy as he mouthed the final word.

Trymon tensed, his fingers curling around the knife again. And Galder opened one eye, nodded at him and sent a sideways blast of power that picked the younger man up and sent him sprawling against the wall.

Galder winked at him and raised his arms again.

‘To me, o spirits of—’

There was a thunderclap, an implosion of light and a moment of complete physical uncertainty during which even the walls seemed to turn in on themselves. Trymon heard a sharp intake of breath and then a dull, solid thump.

The room was suddenly silent.

After a few minutes Trymon crawled out from behind a chair and dusted himself off. He whistled a few bars of nothing much and turned towards the door with exaggerated care, looking at the ceiling as if he had never seen it before. He moved in a way that suggested he was attempting the world speed record for the nonchalant walk.

The Luggage squatted in the centre of the circle and opened its lid.

Trymon stopped. He turned very, very carefully, dreading what he might see.

The Luggage seemed to contain some clean laundry, smelling slightly of lavender. Somehow it was quite the most terrifying thing the wizard had ever seen.

‘Well, er,’ he said. ‘You, um, wouldn’t have seen another wizard around here, by any chance?’

The Luggage contrived to look more menacing.

‘Oh,’ said Trymon. ‘Well, fine. It doesn’t matter.’

He pulled vaguely at the hem of his robe and took a brief interest in the detail of its stitching. When he looked up the horrible box was still there.

‘Goodbye,’ he said, and ran. He managed to get through the door just in time.

‘Rincewind?’

Rincewind opened his eyes. Not that it helped much. It just meant that instead of seeing nothing but blackness he saw nothing but whiteness which, surprisingly, was worse.

‘Are you all right?’

‘No.’

‘Ah.’

Rincewind sat up. He appeared to be on a rock speckled with snow, but it didn’t seem to be everything a rock ought to be. For example, it shouldn’t be moving.

Snow blew around him. Twoflower was a few feet away, a look of genuine concern on his face.

Rincewind groaned. His bones were very angry at the treatment they had recently received and were queuing up to complain.

‘What now?’ he said.

You know when we were flying and I was worried we might hit something in the storm and you said the only thing we could possibly hit at this height was a cloud stuffed with rocks?’

‘Well?’

‘How did you know?’

Rincewind looked around, but for all the variety and interest in the scene around him they might as well have been in the inside of a pingpong ball.

The rock underneath was—well, rocking. He ran his hands over it, and felt the scoring of chisels. When he put an ear to the cold wet stone he fancied he could hear a dull, slow thumping, like a heartbeat. He crawled forward until he came to an edge, and peered very cautiously over it.

At that moment the rock must have been passing over a break in the clouds, because he caught a dim but horribly distant view of jagged-edged mountain peaks.

They were a long way down.

He gurgled incoherently and inched his way backwards.

‘This is ridiculous,’ he told Twoflower. ‘Rocks don’t fly. They’re noted for not doing it.’

‘Maybe they would if they could,’ said Twoflower. ‘Perhaps this one just found out how.’

‘Let’s just hope it doesn’t forget again,’ said Rincewind. He huddled up in his soaking robe and looked glumly at the cloud around him. He supposed there were some people somewhere who had some control over their lives; they got up in the mornings, and went to bed at night in the reasonable certainty of not falling over the edge of the world or being attacked by lunatics or waking up on a rock with ideas above its station. He dimly remembered leading a life like that once.