So the more typical method was to be sponsored by a senior and respected wizard, after a suitable period of apprenticeship.

Competition was stiff for a University place and the honour and privileges an Unseen degree could bring. Many of the boys milling around the hall, and launching minor spells at each other, would fail and have to spend their lives as lowly magicians, mere magical technologists with defiant beards and leather patches on their elbows who congregated in small jealous groups at parties.

Not for them the coveted pointy hat with optional astrological symbols, or the impressive robes, or the staff of authority. But at least they could look down on conjurers, who tended to be jolly and fat and inclined to drop their aitches and drink beer and go around with sad thin women in spangly tights and really infuriate magicians by not realising how lowly they were and kept telling them jokes. Lowliest of all - apart from witches, of course - were thaumaturgists, who never got any schooling at all. A thaumaturgist could just about be trusted to wash out an alembic. Many spells required things like mould from a corpse dead of crushing, or the semen of a living tiger, or the root of a plant that gave an ultrasonic scream when it was uprooted. Who was sent to get them? Right.

It is a common error to refer to the lower magical ranks as hedge wizards. In fact hedge wizardry is a very honoured and specialised form of magic that attracts silent, thoughtful men of the druidical persuasion and topiaric inclinations. If you invited a hedge wizard to a party he would spend half the evening talking to your potted plant. And he would spend the other half listening.

Esk noticed that there were some women in the hall, because even young wizards had mothers and sisters. Whole families had turned up to bid the favoured sons farewell. There was a considerable blowing of noses, wiping of tears and the clink of coins as proud fathers tucked a little spending money into their offspring's hands.

Very senior wizards were perambulating among the crowds, talking to the sponsoring wizards and examining the prospective students.

Several of them pushed through the throng to meet Treatle, moving like gold-trimmed galleons under full sail. They bowed gravely to him and looked approvingly at Simon.

“This is young Simon, is it?” said the fattest of them, beaming at the boy. “We've heard great reports of you, young man. Eh? What?”

“Simon, bow to Archchancellor Cutangle, Archmage of the Wizards of the Silver Star,” said Treatle. Simon bowed apprehensively.

Cutangle looked at him benevolently. “We've heard great things about you, my boy,” he said. “All this mountain air must be good for the brain, eh?”

He laughed. The wizards around him laughed. Treatle laughed. Which Esk thought was rather funny, because there wasn't anything particularly amusing happening.

“I ddddon't know, ssss-”

“From what we hear it must be the only thing you don't know, lad!” said Cutangle, his jowls waggling. There was another carefully timed bout of laughter.

Cutangle patted Simon on the shoulder.

“This is the scholarship boy,” he said. “Quite astounding results, never seen better. Self-taught, too. Astonishing, what? Isn't that so, Treatle?”

“Superb, Archchancellor.”

Cutangle looked around at the watching wizards.

“Perhaps you could give us a sample,” he said. “A little demonstration, perhaps?”

Simon looked at him in animal panic.

“A-actually I'm not very g-g-g-”

“Now, now,” said Cutangle, in what he probably really did think was an encouraging tone of voice. “Do not be afraid. Take your time. When you are ready.”

Simon licked his dry lips and gave Treatle a look of mute appeal.

“Um,” he said, “y-you s-s-s-s-.” He stopped and swallowed hard. “The f-f-f-f-”

His eyes bulged. The tears streamed from his eyes, and his shoulders heaved.

Treatle patted him reassuringly on the back.

“Hayfever,” he explained. “Don't seem to be able to cure it. Tried everything.”

Simon swallowed, and nodded. He waved Treatle away with his long white hands and closed his eyes.

For a few seconds nothing happened. He stood with his lips moving soundlessly, and then silence spread out from him like candlelight. Ripples of noiselessness washed across the crowds in the hall, striking the walls with all the force of a blown kiss and then curling back in waves. People watched their companions mouthing silently and then went red with effort when their own laughter was as audible as a gnat's squeak.

Tiny motes of light winked into existence around his head. They whirled and spiralled in a complex three-dimensional dance, and then formed a shape.

In fact it seemed to Esk that the shape had been there all the time, waiting for her eyes to see it, in the same way that a perfectly innocent cloud can suddenly become, without changing in any way, a whale or a ship or a face.

The shape around Simon's head was the world.

That was quite clear, although the glitter and rush of the little lights blurred some of the detail. But there was Great A'Tuin the sky turtle, with the four Elephants on its back, and on them the Disc itself. There was the sparkle of the great waterfall around the edge of the world, and there at the very hub a tiny needle of rock that was the great mountain Cori Celesti, where the gods lived.

The image expanded and homed in on the Circle Sea and then on Ankh itself, the little lights flowing away from Simon and winking out of existence a few feet from his head. Now they showed the city from the air, rushing towards the watchers. There was the University itself, growing larger. There was the Great Hall

- there were the people, watching silent and open-mouthed, and Simon himself, outlined in specks of silver light. And a tiny sparkling image in the air around him, and that image contained an image and another and another

There was a feeling that the universe had been turned inside out in all dimensions at once. It was a bloated, swollen sensation. It sounded as though the whole world had said “gloop”.

The walls faded. So did the floor. The paintings of former great mages, all scrolls and beards and slightly constipated frowns, vanished. The tiles underfoot, a rather nice black and white pattern, evaporated - to be replaced by fine sand, grey as moonlight and cold as ice. Strange and unexpected stars glittered overhead; on the horizon were low hills, eroded not by wind or rain in this weatherless place but by the soft sandpaper of Time itself.

No one else seemed to have noticed. No one else, in fact, seemed alive. Esk was surrounded by people as still and silent as statues.

And they weren't alone. There were other-Things-behind them, and more were appearing all the time. They had no shape, or rather they seemed to be taking their shapes at random from a variety of creatures; they gave the impression that they had heard about arms and legs and jaws and claws and organs but didn't really know how they all fitted together. Or didn't care. Or were so hungry they hadn't bothered to find out.

They made a sound like a swarm of flies.

They were the creatures out of her dreams, come to feed on magic. She knew they weren't interested in her now, except in the nature of an after-dinner mint. Their whole concentration was focused on Simon, who was totally unaware of their presence.

Esk kicked him smartly on the ankle.

The cold desert vanished. The real world rushed back. Simon opened his eyes, smiled faintly, and gently fell backwards into Esk's arms.

A buzz went up from the wizards, and several of them started to clap. No one seemed to have noticed anything odd, apart from the silver lights.

Cutangle shook himself, and raised a hand to quell the crowd.

“Quite - astonishing,” he said to Treatle. “You say he worked it out all by himself?”

“Indeed, lord.”

“No one helped him at all?”

“There was no one to help him,” said Treatle. “He was just wandering from village to village, doing small spells. But only if people paid him in books or paper.”

Cutangle nodded. “It was no illusion,” he said, “yet he didn't use his hands. What was he saying to himself? Do you know?”

“He says it's just words to make his mind work properly,” said Treatle, and shrugged. “I can't understand half of what he says and that's a fact. He says he's having to invent words because there aren't any for the things he's doing.”

Cutangle glanced sideways at his fellow mages. They nodded.

“It will be an honour to admit him to the University,” he said. “Perhaps you would tell him so when he wakes up.”

He felt a tugging at his robe, and looked down.

“Excuse me,” said Esk.

“Hallo, young lady,” said Cutangle, in a sugarmouse voice. “Have you come to see your brother enter the University?”

“He's not my brother,” said Esk. There were times when the world had seemed to be full of brothers, but this wasn't one of them.

“Are you important?” she said.

Cutangle looked at his colleagues, and beamed. There were fashions in wizardry, just like anything else; sometimes wizards were thin and gaunt and talked to animals (the animals didn't listen, but it's the thought that counts) while at other times they tended towards the dark and saturnine, with little black pointed beards. Currently Aldermanic was in. Cutangle swelled with modesty.

“Quite important,” he said. “One does one's best in the service of one's fellow man. Yes. Quite important, I would say.”

“I want to be a wizard,” said Esk.

The lesser wizards behind Cutangle stared at her as if she was a new and interesting kind of beetle. Cutangle's face went red and his eyes bulged. He looked down at Esk and seemed to be holding his breath. Then he started to laugh. It started somewhere down in his extensive stomach regions and worked its way up, echoing from rib to rib and causing minor wizardquakes across his chest until it burst forth in a series of strangled snorts. It was quite fascinating to watch, that laugh. It had a personality all of its own.

But he stopped when he saw Esk's stare. If the laugh was a music hall clown then Esk's determined squint was a whitewash bucket on a fast trajectory.

“A wizard?” he said; “You want to be a wizard?”

“Yes,” said Esk, pushing the dazed Simon into Trestle's reluctant arms. “I'm the eighth son of an eighth son. I mean daughter.”

The wizards around her were looking at one another and whispering. Esk tried to ignore them.

“What did she say?”

“Is she serious?”

“I always think children are so delightful at that age, don't you?”

“You're the eighth son of an eighth daughter?” said Cutangle. “Really?”

“The other way around, only not exactly,” said Esk, defiantly.

Cutangle dabbed his eyes with a handkerchief.

“This is quite fascinating,” he said. “I don't think I've ever heard of something quite like this before. Eh?”

He looked around at his growing audience. The people at the back couldn't see Esk and were craning to check if some interesting magic was going on. Cutangle was at a loss.

“Well, now,” he said. “You want to be a wizard?”

“I keep telling everyone but no one seems to listen,” said Esk.