Rincewind swallowed. 'Tall man?' he said. 'Fair hair, looks a bit like a ferret?'

'Now that you mention it —'

'He was in my class,' said Rincewind. 'They always said he'd go a long way.'

'He'll go a lot further if he opens the book,' said one of the wizards, who was hastily rolling a cigarette in shaking fingers.

'Why?' said Twoflower. 'What will happen?'

The wizards looked at one another.

'It's an ancient secret, handed down from mage to mage, and we can't pass it on to knowlessmen,' said Wert.

'Oh, go on,' said Twoflower.

'Oh well, it probably doesn't matter any more. One mind can't hold all the spells. It'll break down, and leave a hole.'

'What? In his head?'

'Um. No. In the fabric of the Universe,' said Wert. 'He might think he can control it by himself, but —'

They felt the sound before they heard it. It started off in the stones as a slow vibration, then rose suddenly to a knife-edge whine that bypassed the eardrums and bored straight into the brain. It sounded like a human voice singing, or chanting, or screamfng, but there were deeper and more horrible harmonics.

The wizards went pale. Then, as one man, they turned and ran up the steps.

There were crowds outside the building. Some people were holding torches, others had stopped in the act of piling kindling around the walls. But everyone was staring up at the Tower of Art.

The wizards pushed their way through the unheeding bodies, and turned to look up.

The sky was full of moons. Each one was three times bigger than the Disc's own moon, and each was in shadow except for a pink crescent where it caught the light of the star.

But in front of everything the top of the Tower of Art was an incandescent fury. Shapes could be dimly glimpsed within it, but there was nothing reassuring about them. The sound had changed now to the wasplike buzzing, magnified a million times.

Some of the wizards sank to their knees.

'He's done it,' said Wert, shaking his head. 'He's opened a pathway.'

'Are those things demons?' said Twoflower.

'Oh, demons,' said Wert. 'Demons would be a picnic compared with what's trying to come through up there.'

'They're worse than anything we can possibly imagine,' said Panter.

'I can imagine some pretty bad things,' said Rincewind.

'These are worse.'

'Oh.'

'And what do you propose to do about it?' said a clear voice.

They turned. Bethan was glaring at them, arms folded.

'Pardon?' said Wert.

'You're wizards, aren't you?' she said. 'Well, get on with it.'

'What, tackle that?' said Rincewind.

'Know anyone else?'

Wert pushed forward. 'Madam, I don't think you quite understand —'

'The Dungeons Dimensions will empty into our Universe, right?' said Bethan.

'Well, yes —'

'We'll all be eaten by things with tentacles for faces, right?'

'Nothing so pleasant, but —'

'And you're just going to let it happen?'

'Listen,' said Rincewind. 'It's all over, do you see? You can't put the spells back in the book, you can't unsay what's been said, you can't —'

'You can try!'

Rincewind sighed, and turned to Twoflower.

He wasn't there. Rincewind's eyes turned inevitably towards the base of the Tower of Art, and he was just in time to see the tourist's plump figure, sword inexpertly in hand, as it disappeared into a door.

Rincewind's feet made their own decision and, from the oint of view of his head, got it entirely wrong.

The other wizards watched him go.

'Well?' said Bethan. 'He's going.' . The wizards tried to avoid one another's eyes.

Eventually Wert said, 'We could try, I suppose. It doesn't seem to be spreading.'

'But we've got hardly any magic to speak of,' said one of the wizards.

'Have you got a better idea, then?'

One by one, their ceremonial robes glittering in the weird light, the wizards turned and trudged towards the tower.

The tower was hollow inside, with the stone treads of its staircase mortared spiral-fashion into the walls. Twoflower was already several turns up by the time Rincewind caught him.

'Hold on,' he said, as cheerfully as he could manage. 'This sort of thing is a job for the likes of Cohen, not you. No offence.'

'Would he do any good?'

Rincewind looked up at the actinic light that lanced down through the distant hole at the top of the staircase.

'No,' he admitted.

Then I'd be as good as him, wouldn't I?' said Twoflower, flourishing his looted sword.

Rincewind hopped after him, keeping as close to the wall as possible.

'You don't understand!' he shouted. There's unimaginable horrors up there!'

'You always said I didn't have any imagination.'

'It's a point, yes,' Rincewind conceded, 'but —'

Twoflower sat down.

'Look,' he said. 'I've been looking forward to something like this ever since I came here. I mean, this is an adventure, isn't it? Alone against the gods, that sort of thing?'

Rincewind opened and shut his mouth for a few seconds before the right words managed to come out.

'Can you use a sword?' he said weakly.

'I don't know. I've never tried.'

'You're mad!'

Twoflower looked at him with his head on one side. 'You're a fine one to talk,' he said. 'I'm here because I don't know any better, but what about you?' He pointed downwards, to where the other wizards were toiling up the stairs. 'What about them?'

Blue light speared down the inside of the tower. There was a peal of thunder.

The wizards reached them, coughing horribly and fighting for breath.

'What's the plan?' said Rincewind.

'There isn't one,' said Wert.

'Right. Fine,' said Rincewind. 'I'll leave you to get on with it, then.'

'You'll come with us,' said Panter.

'But I'm not even a proper wizard. You threw me out, remember?'

'I can't think of any student less able,' said the old wizard, 'but you're here, and that's the only qualification you need. Come on.'

The light flared and went out. The terrible noises died as if strangled.

Silence filled the tower; one of those heavy, pressing silences.

'It's stopped,' said Twoflower.

Something moved, high up against the circle of red sky. It fell slowly, turning over and over and drifting from side to side. It hit the stairs a turn above them.

Rincewind was first to it.

It was the Octavo. But it lay on the stone as limp and lifeless as any other book, its pages fluttering in the breeze that blew up the tower.

Twoflower panted up behind Rincewind, and looked down.

'They're blank,' he whispered. 'Every page is completely blank.'

'Then he did it,' said Wert. 'He's read the spells. Successfully, too. I wouldn't have believed it.'

'There was all that noise,' said Rincewind doubtfully. 'The light, too. Those shapes. That didn't sound so successful to me.'

'Oh, you always get a certain amount of extradimen-sional attention in any great work of magic,' said Panter dismissively. 'It impresses people, nothing more.'

'It looked like monsters up there,' said Twoflower, standing closer to Rincewind.

'Monsters? Show me some monsters!' said Wert.

Instinctively they looked up. There was no sound. Nothing moved against the circle of light.

'I think we should go up and, er, congratulate him,' said Wert.

'Congratulate?' exploded Rincewind. 'He stole the Octavo! He locked you up!'

The wizards exchanged knowing looks.

'Yes, well,' said one of them. 'When you've advanced in the craft, lad, you'll know that there are times when the important thing is success.'

'It's getting there that matters,' said Wert bluntly. 'Not how you travel.'

They set off up the spiral.

Rincewind sat down, scowling at the darkness.

He felt a hand on his shoulder. It was Twoflower, who was holding the Octavo.

'This is no way to treat a book,' he said. 'Look, he's bent the spine right back. People always do that, they've got no idea of how to treat them.'

'Yah,' said Rincewind vaguely.

'Don't worry,' said Twoflower.

'I'm not worried, I'm just angry,' snapped Rincewind. 'Give me the bloody thing!'

He snatched the book and snapped it open viciously.

He rummaged around in the back of his mind, where the Spell hung out.

'All right,' he snarled. You've had your fun, you've ruined my life, now get back to where you belong!'

'But I—' protested Twoflower.

'The Spell, I mean the Spell,' said Rincewind. 'Go on, get back on the page!'

He glared at the ancient parchment until his eyes crossed.

'Then I'll say you!' he shouted, his voice echoing up the tower. 'You can join the rest of them and much good may it do you!'

He shoved the book back into Twoflower's arms and staggered off up the steps.

The wizards had reached the top and disappeared from view. Rincewind climbed after them.

'Lad, am I?' he muttered. 'When I'm advanced in the craft, eh? I just managed to go around with one of the Great Spells in my head for years without going totally insane, didn't I?' He considered the last question from all angles. Yes, you did,' he reassured himself. 'You didn't start talking to trees, even when trees started talking to you.'

His head emerged into the sultry air at the top of the tower.

He had expected to see fire-blackened stones criss-crossed with talon marks, or perhaps something even worse.

Instead he saw the seven senior wizards standing by Trymon, who seemed totally unscathed. He turned and smiled pleasantly at Rincewind.

'Ah, Rincewind. Come and join us, won't you?'

So this is it, Rincewind thought. All that drama for nothing. Maybe I really am not cut out to be a wizard, maybe —

He looked up and into Trymon's eyes.

Perhaps it was the Spell, in its years of living in Rincewind's head, that had affected his eyes. Perhaps his time with Twoflower, who only saw things as they ought to be, had taught him to see things as they are.

But what was certain was that by far the most difficult thing Rincewind did in his whole life was look at Trymon without running in terror or being very violently sick.

The others didn't seem to have noticed.

They also seemed to be standing very still.

Trymon had tried to contain the seven Spells in his mind and it had broken, and the Dungeon Dimensions had found their hole, all right. Silly to have imagined that the Things would have come marching out of a sort of rip in the sky, waving mandibles and tentacles. That was old-fashioned stuff, far too risky. Even nameless terrors learned to move with the times. All they really needed to enter was one head.

His eyes were empty holes.

Knowledge speared into Rincewind's mind like a knife of ice. The Dungeon Dimensions would be a playgroup compared to what the Things could do in a universe of order. People were craving order, and order they would get – the order of the turning screw, the immutable law of straight lines and numbers. They would beg for the harrow . . .

Trymon was looking at him. Something was looking at him. And still the others hadn't noticed. Could he even explain it? Trymon looked the same as he had always done, except for the eyes, and a slight sheen to his skin.

Rincewind stared, and knew that there were far worse things than Evil. All the demons in Hell would torture your very soul, but that was precisely because they valued souls very highly; evil would always try to steal the universe, but at least it considered the universe worth stealing. But the grey world behind those empty eyes would trample and destroy without even according its victims the dignity of hatred. It wouldn't even notice them.

Trymon held out his hand.