"Then getting away before it finds it is a first-class idea, don't you think?"

A tongue of fire hit the dark Tower of Art, slid blindly down its ivy-grown flanks, and disappeared through the dome of Unseen University's Library.

The other lines blinked out.

Lady Ramkin brought the coach to a halt at the far side of the square.

"What does it want the Library for?" she said, frown­ing.

"Maybe it wants to look something up?"

"Don't be silly," she said breezily. "There's just a lot of books hi there. What would a flash of lightning want to read?"

"Something very short?"

"I really think you could try to be a bit more help."

The line of light exploded into an arc between the Li­brary's dome and the centre of the plaza and hung hi the air, a band of brilliance several feet across.

Then, hi a sudden rush, it became a sphere of fire which grew swiftly to encompass almost all the plaza, vanished suddenly, and left the night full of ringing, violet shad­ows.

And the plaza full of dragon.

Who would have thought it? So much power, so close at hand. The dragon could feel the magic flowing into it, renewing it from second to second, in defiance of all bor­ing physical laws. This wasn't the poor feed it had been given before. This was the right stuff. There was no end to what it could do, with power like this.

But first it had to pay its respects to certain people . . .

It sniffed the dawn air. It was searching for the stink of minds.

Noble dragons don't have friends. The nearest they can get to the idea is an enemy who is still alive.

The air became very still, so still that you could almost hear the slow fall of dust. The Librarian swung on his knuckles between the endless bookshelves. The dome of the Library was still overhead but then, it always was.

It seemed quite logical to the Librarian that, since there were aisles where the shelves were on the outside then there should be other aisles in the space between the books themselves, created out of quantum ripples by the sheer weight of words. There were certainly some odd sounds coming from the other side of some shelving, and the Librarian knew that if he gently pulled out a book or two he would be peeking into different libraries under different skies.

Books bend space and time. One reason the owners of those aforesaid little rambling, poky second-hand book­shops always seem slightly unearthly is that many of them really are, having strayed into this world after taking a wrong turn in their own bookshops in worlds where it is considered commendable business practice to wear car­pet slippers all the time and open your shop only when you feel like it. You stray into L-space at your peril.

Very senior librarians, however, once they have proved themselves worthy by performing some valiant act of librarianship, are accepted into a secret order and are taught the raw arts of survival beyond the Shelves We Know. The Librarian was highly skilled in all of them, but what he was attempting now wouldn't just get him thrown out of the Order but probably out of life itself.

All libraries everywhere are connected in L-space. All libraries. Everywhere. And the Librarian, navigating by booksign carved on shelves by past explorers, navigating by smell, navigating even by the siren whisperings of nos­talgia, was heading purposely for one very special one.

There was one consolation. If he got it wrong, he'd never know it.

Somehow the dragon was worse on the ground. In the air it was an elemental thing, graceful even when it was trying to burn you to your boots. On the ground it was just a damn great animal.

Its huge head reared against the gray of dawn, turning slowly.

Lady Ramkin and Vimes peered cautiously from be­hind a water trough. Vimes had his hand clamped over Errol's muzzle. The little dragon was whimpering like a kicked puppy, and fighting to get away.

"It's a magnificent brute," said Lady Ramkin, in what she probably thought was a whisper.

"I do wish you wouldn't keep saying that,'' said Vimes.

There was a scraping noise as the dragon dragged itself over the stones.

"I knew it wasn't killed,'' growled Vimes. "There were no bits. It was too neat. It was sent somewhere by some sort of magic, I bet. Look at it. It's bloody impossible! It needs magic to keep it alive!"

"What do you mean?" said Lady Ramkin, not tearing her gaze from its armoured flanks.

What did he mean? What did he mean? He thought fast.

"It's just not physically possible, that's what I mean," he said. "Nothing that heavy should be able to fly, or breathe fire like that. I told you. But it looks real enough. I mean, you'd expect a mag­ical creature to be, well, gauzy."

"Oh, it's real. It's real all right," said Ramkin bitterly. "But supposing it needs magic like we need, like we need . . . sunlight? Or food."

"It's a thaumivore, you mean?"

"I just think it eats magic, that's all," said Vimes, who had not had a classical education. "I mean, all these little swamp dragons, always on the point of extinction, sup­pose one day back in prehistoric times some of them found out how to use magic?"

"There used to be a lot of natural magic around once,'' said Lady Ramkin thoughtfully.

"There you are, then. After all, creatures use the air and the sea. I mean, if there's a natural resource around, something's going to use it, aren't they? Then it wouldn't matter about bad digestion and weight and wing size and so on, because the magic would take care of it. Wow!"

But you'd need a lot, he thought. He wasn't certain how much magic you'd need to change the world enough to let tons of armoured carcass flit around the sky like a swal­low, but he'd bet it was lots.

All those thefts. Someone'd been feeding the dragon.

He looked at the bulk of the Unseen University Library of magic books, the greatest accumulation of distilled magical power on the Discworld.

And now the dragon had learned how to feed itself.

He became terribly aware that Lady Ramkin had moved, and saw to his horror that she was striding towards the dragon, chin stuck out like an anvil.

"What the hell are you doing?" he whispered loudly.

"If it's descended from the swamp dragons then I can probably control it," she called back. "You have to look them in the eye and use a no-nonsense tone of voice. They can't resist a stern human voice. They don't have the will­power, you know. They're just big softies."