In the square outside the gates several large bonfires had been lit, for effect as much as anything else, because the heat from the star was scorching.

‘But you can still see the stars,’ said Twoflower, ‘the ther stars, I mean. The little ones. In a black sky.’

Rincewind ignored him. He was looking at the gates. A group of star people and citizens were trying to batter them down.

‘It’s hopeless,’ said Bethan. ‘We’ll never get in. Where are you going?’

‘For a walk,’ said Rincewind. He was setting off determinedly down a side street.

There were one or two freelance rioters here, mostly engaged in wrecking shops. Rincewind took no notice, but followed the wall until it ran parallel to a dark alley that had the usual unfortunate smell of all alleys, everywhere.

Then he started looking very closely at the stonework. The wall here was twenty feet high, and topped with cruel metal spikes.

‘I need a knife,’ he said.

‘You’re going to cut your way through?’ said Bethan.

‘Just find me a knife,’ said Rincewind. He started to tap stones.

Twoflower and Bethan looked at each other, and shrugged. A few minutes later they returned with a selection of knives, and Twoflower had even managed to find a sword.

‘We just helped ourselves,’ said Bethan.

‘But we left some money,’ said Twoflower. ‘I mean, we would have left some money, if we’d had any —’

‘So he insisted on writing a note,’ said Bethan wearily.

Twoflower drew himself up to his full height, which was hardly worth it.

‘I see no reason—’ he began, stiffly.

‘Yes, yes,’ said Bethan, sitting down glumly. ‘I know you don’t. Rincewind, all the shops have been smashed open, there was a whole bunch of people across the street helping themselves to musical instruments, can you believe that?’

‘Yeah,’ said Rincewind, picking up a knife and testing its blade thoughtfully. ‘Luters, I expect.’

He thrust the blade into the wall, twisted it, and stepped ack as a heavy stone fell out. He looked up, counting under his breath, and levered another stone from its socket.

‘How did you do that?’ said Twoflower.

‘Just give me a leg up, will you?’ said Rincewind. A moment later, his feet wedged into the holes he had created, he was making further steps halfway up the wall.

‘It’s been like this for centuries,’ his voice floated down. ‘Some of the stones haven’t got any mOrtar. Secret entrance, see? Watch out below.’

Another stone cracked into the cobbles.

‘Students made it long ago,’ said Rincewind. ‘Handy way in and out after lights out.’

‘Ah,’ said Twoflower, ‘I understand. Over the wall and out to brightly-lit tavernas to drink and sing and recite poetry, yes?’

‘Nearly right except for the singing and the poetry, yes,’ said Rincewind. ‘A couple of these spikes should be loose—’ There was a clang.

‘There’s not much of a drop this side,’ came his voice after a few seconds. ‘Come on, then. If you’re coming.’

And so it was that Rincewind, Twoflower and Bethan entered Unseen University.

Elsewhere on the campus—

The eight wizards inserted their keys and, with many a worried glance at one another, turned them. There was a faint little snicking sound as the lock slid open.

The Octavo was unchained. A faint octarine light played across its bindings.

Trymon reached out and picked it up, and none of the others objected. His arm tingled.

He turned towards the door.

‘Now to the Great Hall, brothers,’ he said, ‘if I may lead the way —’

And there were no objections.

He reached the door with the book tucked under his rm. It felt hot, and somehow prickly.

At every step he expected a cry, a protest, and none came. He had to use every ounce of control to stop himself from laughing. It was easier than he could have imagined.

The others were halfway across the claustrophobic dungeon by the time he was through the door, and perhaps they had noticed something in the set of his shoulders, but it was too late because he had crossed the threshold, gripped the handle, slammed the door, turned the key, smiled the smile.

He walked easily back along the corridor, ignoring the enraged screams of the wizards who had just discovered how impossible it is to pass spells in a room built to be impervious to magic.

The Octavo squirmed, but Trymon held it tightly. Now he ran, putting out of his mind the horrible sensations under his arm as the book shape-changed into things hairy, skeletal and spiky. His hand went numb. The faint chittering noises he had been hearing grew in volume, and there were other sounds behind them—leering sounds, beckoning sounds, sounds made by the voices of unimaginable horrors that Trymon found it all too easy to imagine. As he ran across the Great Hall and up the main staircase the shadows began to move and reform and close in around him, and he also became aware that something was following, something with skittery legs moving obscenely fast. Ice formed on the walls. Doorways lunged at him as he barrelled past. Underfoot the stairs began to feel just like a tongue...

Not for nothing had Trymon spent long hours in the University’s curious equivalent of a gymnasium, building up mental muscle. Don’t trust the senses, he knew, because they can be deceived. The stairs are there, somewhere—will them to be there, summon them into being as you climb and, boy, you better get good at it. Because this isn’t all imagination.

Great A’Tuin slowed.

With flippers the size of continents the skyturtle fought the pull of the star, and waited. There would not be long to wait...

Rincewind sidled into the Great Hall. There were a few torches burning, and it looked as though it had been set up for some sort of magical work. But the ceremonial candlesticks had been overturned, the complex octograms chalked on the floor were scuffed as if something had danced on them, and the air was full of a smell unpleasant even by Ankh-Morpork’s broad standards. There was a hint of sulphur to it, but that underlay something worse. It smelt like the bottom of a pond.

There was a distant crash, and a lot of shouting.

‘Looks like the gates have gone down,’ said Rincewind.

‘Let’s get out of here,’ said Bethan.

‘The cellars are this way,’ said Rincewind, and set off through an arch.

‘Down there!’

‘Yes. Would you rather stay here?’

He took a torch from its bracket on the wall and started down the steps.

After a few flights the walls stopped being panelled and were bare stone. Here and there heavy doors had been propped open.

‘I heard something,’ said Twoflower.

Rincewind listened. There did seem to be a noise coming from the depths below. It didn’t sound frightening. It sounded like a lot of people hammering on a door and shouting ‘Oi!’

‘It’s not those Things from the Dungeon Dimensions you were telling us about, is it?’ said Bethan.

They don’t swear like that,’ said Rincewind. ‘Come on.’

They hurried along the dripping passages, following the screamed curses and deep hacking coughs that were somehow reassuring; anything that wheezed like that, the listeners decided, couldn’t possibly represent a danger.

At last they came to a door set in an alcove. It looked strong enough to hold back the sea. There was a tiny grille.

‘Hey!’ shouted Rincewind. It wasn’t very useful, but he couldn’t think of anything better.

There was a sudden silence. Then a voice from the other side of the door said, very slowly, Who is out there?’

Rincewind recognised that voice. It had jerked him from daydreams into terror on many a hot classroom afternoon, years before. It was Lemuel Panter, who had once made it his personal business to hammer the rudiments of scrying and summoning into young Rincewind’s head. He remembered the eyes like gimlets in a piggy face and the voice saying ‘And now Mister Rincewind will come out here and draw the relevant symbol on the board’ and the million mile walk past the waiting class as he tried desperately to remember what the voice had been droning on about five minutes before. Even now his throat was going dry with terror and randomised guilt. The Dungeon Dimensions just weren’t in it.