He sat back and beamed.

The rest of the council exchanged glances.

"The drains don't sound like hurrying feet, Archchancellor," said the Bursar wearily.

"Unless someone left a tap running," said the Senior Tutor.

The Bursar scowled at him. He'd been in the tub when the invisible screaming thing had hurtled through his room. It was not an experience he wanted to repeat.

The Archchancellor nodded at him.

"That's settled, then," he said, and fell asleep.

The Bursar watched him in silence. Then he pulled the old man's hat off and tucked it gently under his head.

"Well?" he said wearily. "Has anyone got any suggestions?"

The Librarian put his hand up.

"Oook," he said.

"Yes, well done, good boy," said the Bursar, breezily. "Anyone else?"

The orang-utan glared at him as the other wizards shook their heads.

"It's a tremor in the texture of reality," said the Senior Tutor. "That's what it is."

"What should we do about it, then?"

"Search me. Unless we tried the old -"

"Oh, no," said the Bursar. "Don't say it. Please. It's far too dangerous -"

His words were chopped off by a scream that began at the far end of the room and dopplered along the table, accompanied by the sound of many running feet. The wizards ducked in a scatter of overturned chairs.

The candle flames were drawn into long thin tongues of octarine light before being snuffed out.

Then there was silence, the special kind that you get after a really unpleasant noise.

And the Bursar said, "All right. I give in. We will try the Rite of AshkEnte."

It is the most serious ritual eight wizards can undertake. It summons Death, who naturally knows everything that is going on everywhere.

And of course it is done with reluctance, because senior wizards are generally very old and would prefer not to do anything to draw Death's attention in their direction.