Rincewind said another word.

Then he said, in a lower and more urgent tone, 'Actually, I don't think I can hang on any longer.'

'Try.'

'It's no good, I can feel my hand slipping!'

Twoflower sighed. It was time for harsh measures. 'All right, then,' he said. 'Drop, then. See if I care.'

'What?' said Rincewind, so astonished he forgot to let go.

'Go on, die. Take the easy way out.'

'Easy?' .

'All you have to do is plummet screaming through the air and break every bone in your body,' said Twoflower. 'Anybody can do it. Go on. I wouldn't want you to think that perhaps you ought to stay alive because we need you to say the Spells and save the Disc. Oh, no. Who cares if we all get burned up? Go on, just think of yourself. Drop.'

There was a long, embarrassed silence.

'I don't know why it is,' said Rincewind eventually, in a voice rather louder than necessary, 'but ever since I met you I seem to have spent a lot of time hanging by my fingers over certain depth, have you noticed?'

'Death,' corrected Twoflower.

'Death what?' said Rincewind.

'Certain death,' said Twoflower helpfully, trying to ignore the slow but inexorable slide of his body across the flagstones. 'Hanging over certain death. You don't like heights.'

'Heights I don't mind,' said Rincewind's voice from the darkness. 'Heights I can live with. It's depths that are occupying my attention at the moment. Do you know what I'm going to do when we get out of this?'

'No?' said Twoflower, wedging his toes into a gap in the flagstones and trying to make himself immobile by sheer force of will.

'I'm going to build a house in the flattest country I can find and it's only going to have a ground floor and I'm not even going to wear sandals with thick soles —'

The leading torch came around the last turn of the spiral and Twoflower looked down on the grinning face of Cohen. Behind him, still hopping awkwardly up the stones, he could make out the reassuring bulk of the Luggage.

'Everything all right?' said Cohen. 'Can I do anything?'

Rincewind took a deep breath.

Twoflower recognised the signs. Rincewind was about to say something like, 'Yes, I've got this itch on the back of my neck, you couldn't scratch it, could you, on your way past?' or 'No, I enjoy hanging over bottomless drops' and he decided he couldn't possibly face that. He spoke very quickly.

'Pull Rincewind back onto the stairs,' he snapped. Rincewind deflated in mid-snarl.

Cohen caught him around the waist and jerked him unceremoniously onto the stones.

'Nasty mess down on the floor down there,' he said conversationally. 'Who was it?'

'Did it—' Rincewind swallowed, 'did it have – you know – tentacles and things?'

'No,' said Cohen. 'Just the normal bits. Spread out a bit, of course.'

Rincewind looked at Twoflower, who shook his head.

'Just a wizard who let things get on top of him,' he said.

Unsteadily, with his arms screaming at him, Rincewind let himself be helped back onto the roof of the tower.

'How did you get here?' he added.

Cohen pointed to the Luggage, which had trotted over 203 to Twoflower and opened its lid like a dog that knows it's been bad and is hoping that a quick display of affection may avert the rolled-up newspaper of authority.

'Bumpy but fast,' he said admiringly. 'I'll tell you this, no-one tries to stop you.'

Rincewind looked up at the sky. It was indeed full of moons, huge cratered discs now ten times bigger than the Disc's tiny satellite. He looked at them without much interest. He felt washed out and stretched well beyond breaking point, as fragile as ancient elastic.

He noticed that Twoflower was trying to set up his picture box.

Cohen was looking at the seven senior wizards.

'Funny place to put statues,' he said. 'No-one can see them. Mind you, I can't say they're up to much. Very poor work.'

Rincewind staggered across and tapped Wert gingerly on the chest. He was solid stone.

This is it, he thought. I just want to go home.

Hang on, I am home. More or less. So I just want a good sleep, and perhaps it will all be better in the morning.

His gaze fell on the Octavo, which was outlined in tiny flashes of octarine fire. Oh yes, he thought.

He picked it up and thumbed idly through its pages. They were thick with complex and swirling script that changed and reformed even as he looked at it. It seemed undecided as to what it should be; one moment it was an orderly, matter-of-fact printing; the next a series of angular runes. Then it would be curly Kythian spellscript. Then it would be pictograms in some ancient, evil and forgotten writing that seemed to consist exclusively of unpleasant reptilian beings doing complicated and painful things to one another . . .

The last page was empty. Rincewind sighed, and looked in the back of his mind. The Spell looked back.

He had dreamed of this moment, how he would finally evict the Spell and take vacant possession of his own head and learn all those lesser spells which had, up until hen, been too frightened to stay in his mind. Somehow he had expected it to be far more exciting.

Instead, in utter exhaustion and in a mood to brook no argument, he stared coldly at the Spell and jerked a metaphorical thumb over his shoulder. You. Out.

It looked for a moment as though the Spell was going to argue, but it wisely thought better of it.

There was a tingling sensation, a blue flash behind his eyes, and a sudden feeling of emptiness.

When he looked down at the page it was full of words. They were runes again. He was glad about that, the reptilian pictures were not only unspeakable but probably unpronounceable too, and reminded him of things he would have great difficulty in forgetting.

He looked blankly at the book while Twoflower bustled around unheeded and Cohen tried in vain to lever the rings off the stone wizards.

He had to do something, he reminded himself. What was it, now?

He opened the book at the first page and began to read, his lips moving and his forefinger tracing the outline of each letter. As he mumbled each word it appeared soundlessly in the air beside him, in bright colours that streamed away in the night wind. He turned over the page.

Other people were coming up the steps now – star people, citizens, even some of the Patrician's personal guard. A couple of star people made a half-hearted attempt to approach Rincewind, who was surrounded now by a rainbow swirl of letters and took absolutely no notice of them, but Cohen drew his sword and looked nonchalantly at them and they thought better of it.

Silence spread out from Rincewind's bent form like ripples in a puddle. It cascaded down the tower and spread out through the milling crowds below, flowed over the walls, gushed darkly through the city, and engulfed the lands beyond.

The bulk of the star loomed silently over the Disc. In the sky around it the new moons turned slowly and noiselessly.

The only sound was Rincewind's hoarse whispering as he turned page after page.

'Isn't this exciting!' said Twoflower. Cohen, who was rolling a cigarette from the tarry remnants of its ancestors, looked at him blankly, paper halfway to his lips.

'Isn't what exciting?' he said.

'All this magic!'

'It's only lights,' said Cohen critically. 'He hasn't even produced doves out of his sleeves.'

'Yes, but can't you sense the occult potentiality?' said Twoflower.

Cohen produced a big yellow match from somewhere in his tobacco bag, looked at Wert for a moment, and with great deliberation struck the match on his fossilised nose.

'Look,' he said to Twoflower, as kindly as he could manage. 'What do you expect? I've been around a long time, I've seen the whole magical thing, and I can tell you that if you go around with your jaw dropping all the time people hit it. Anyway, wizard's die just like anyone else when you stick a —'

There was a loud snap as Rincewind shut the book. He stood up, and looked around.

What happened next was this:

Nothing.

It took a little while for people to realise it. Everyone had ducked instinctively, waiting for the explosion of white light or scintillating fireball or, in the case of Cohen, who had fairly low expectations, a few white pigeons, possibly a slightly crumpled rabbit.

It wasn't even an interesting nothing. Sometimes things can fail to happen in quite impressive ways, but as far as non-events went this one just couldn't compete.

'Is that it?' said Cohen. There was a general muttering from the crowd, and several of the star people were looking angrily at Rincewind.

The wizard stared Wearily at Cohen.

'I suppose so,' he said.

'But nothing's happened.'

Rincewind looked blankly at the Octavo.

'Maybe it has a subtle effect?' he said hopefully. 'After all, we don't know exactly what is supposed to happen.'

'We knew it!' shouted one of the star people. 'Magic doesn't work! It's all illusion!'

A stone looped over the roof and hit Rincewind on the shoulder.

'Yeah,' said another star person. 'Let's get him!'

'Let's throw him off the tower!'

'Yeah, let's get him and throw him off the tower!'

The crowd surged forward. Twoflower held up his hands.

'I'm sure there's just been a slight mistake—' he began, before his legs were kicked from underneath him.

'Oh bugger,' said Cohen, dropping his dogend and grinding it under a sandalled foot. He drew his sword and looked around for the Luggage.

It hadn't rushed to Twoflower's aid. It was standing in front of Rincewind, who was clutching the Octavo to his chest like a hot-water bottle and looking frantic.

A star man lunged at him. The Luggage raised its lid threateningly.

'I know why it hasn't worked,' said a voice from the back of the crowd. It was Bethan.

'Oh yeah?' said the nearest citizen. 'And why should we listen to you?'

A mere fraction of a second later Cohen's sword was pressed against his neck.

'On the other hand,' said the man evenly, 'perhaps we should pay attention to what this young lady has got to say.'

As Cohen swung around slowly with his sword at the ready Bethan stepped forward and pointed to the swirling shapes of the spells, which still hung in the air around Rincewind.

'That one can't be right,' she said, indicating a smudge of dirty brown amidst the pulsing, brightly coloured flares.

You must have mispronounced a word. Let's have a look.'

Rincewind passed her the Octavo without a word.

She opened it and peered the pages.

'What funny writing,' she said. 'It keeps changing. What's that crocodile thing doing to the octopus?'

Rincewind looked over her shoulder and, without thinking, told her. She was silent for a moment.

'Oh,' she said levelly. 'I didn't know crocodiles could do that.'

'It's just ancient picture writing,' said Rincewind hurriedly. 'It'll change if you wait. The Spells can appear in every known language.'

'Can you remember what you said when the wrong colour appeared?'

Rincewind ran a finger down the page.

'There, I think. Where the two-headed lizard is doing – whatever it's doing.'

Twoflower appeared at her other shoulder. The Spell flowed into another script.

'I can't even pronounce it,' said Bethan. 'Squiggle, squiggle, dot, dash.'

'That's Cupumuguk snow runes,' said Rincewind. 'I think it should be pronounced “zph”.'

'It didn't work, though. How about “sph”?'

They looked at the word. It remained resolutely off-colour.

'Or “sff”?' said Bethan.

'It might be “tsff”,' said Rincewind doubtfully. If anything the colour became a dirtier shade of brown.