This had to be stopped.

‘I shall need a volunteer,’ he said firmly.

There was a sudden silence. The only sound came from behind the door. It was the nasty little noise of metal parting under stress.

‘Very well, then,’ he said. ‘In that case I shall need some silver tweezers, about two pints of cat’s blood, a small whip and a chair —’

It is said that the opposite of noise is silence. This isn’t true. Silence is only the absence of noise. Silence would have been a terrible din compared to the sudden soft implosion of noiselessness that hit the wizards with the force of an exploding dandelion clock.

A thick column of spitting light sprang up from the book, hit the ceiling in a splash of flame, and disappeared.

Galder stared up at the hole, ignoring the smouldering patches in his beard. He pointed dramatically.

To the upper cellars!’ he cried, and bounded up the stone stairs. Slippers flapping and nightshirts billowing he other wizards followed him, falling over one another in their eagerness to be last.

Nevertheless, they were all in time to see the fireball of occult potentiality disappear into the ceiling of the room above.

‘Urgh,’ said the youngest wizard, and pointed to the floor.

The room had been part of the library until the magic had drifted through, violently reassembling the possibility particles of everything in its path. So it was reasonable to assume that the small purple newts had been part of the floor and the pineapple custard may once have been some books. And several of the wizards later swore that the small sad orang outang sitting in the middle of it all looked very much like the head librarian.

Galder stared upwards. ‘To the kitchen!’ he bellowed, wading through the custard to the next flight of stairs.

No-one ever found out what the great cast-iron cooking range had been turned into, because it had broken down a wall and made good its escape before the dishevelled party of wild-eyed mages burst into the room. The vegetable chef was found much later hiding in the soup cauldron, gibbering unhelpful things like The knuckles! The horrible knuckles!’