The bookshop had not been easy to find. It was tucked down a back alley away from the main shopping streets. At first, Paul thought it closed. The windows were dusty and the light inside dim, but the door opened when he pushed it.

It was like stepping back in time. Dickens would feel at home here, thought Paul. Row upon row of bookshelves crammed the small interior. They even lined the wall of the narrow stairs that disappeared down into the basement. The atmosphere seemed somehow full of books as well, the old books giving up their paper fibre by fibre into the air, so that the room was rank with old words and forgotten sentences.

The proprietor looked as ancient as the books around him. He wore a grey shirt and a lime hand-knitted cardigan that looked as though it would disintegrate in the unlikely event of it ever going near a washing machine. He bent over a book on the counter, licking the forefinger of his left hand to turn the page, dunking digestive biscuits into a mug of dark tea with his right. A track of soggy crumbs across his chest attested to his lack of dunking precision.

"Sex magic is in row three," he said, without looking up.

"No, I'm here for ... sex magic?" asked Paul.

"Row three," repeated the old man.

"No, I'm not here for that. I'm looking for the owner."

The old man read for a few more moments, took an unopened manila letter marked 'final notice' and placed it as a bookmark, shut the book with a slam and finally looked up at Paul. His expression indicated that he did not like what he saw.

"What's your business with him?"

"I ... um ... I have some questions I'd like to ask."

"You with the tax man?"

"No."

"Rent?"

"No, I ..."

"Bailiffs?"

"No, I'm not after any money."

The old man sniffed, as if to say in his experience everyone was after money, but that he was prepared to take him at his word for the moment.

"Who are you, then?"

"My name's Paul. Are you Mister Avery?"

"I might be. What do you want?"

"I have a question about ... well, the occult, I guess. I heard you were an authority."

"Well, you heard wrong, then, didn't you. Don't know nothing about the occult."

"You don't?" asked Paul, unable to hide his disappointment.

"No. Look around you. See them funny rectangular objects. Them's called books, them is. Don't suppose someone your age ever reads books. 'Spect it's all computers and iPods with you lot. What I'm an authority on, Sonny Jim, is occult books. Nothing I don't know about occult books. If it's a question about occult books, I'm your man. I could go on Mastermind, me, specialist subject: occult books. Not the occult, occult books. Understand? Now, if you've got a question about occult books, fire away, otherwise buy a book or piss off."

"I'm looking for a book that tells me how to get rid of a demon," said Paul.

"Oh, is that all?" said Mister Avery. "Get rid of a demon? Oh, I have a hundred books on that. That's easy."

"It is?" asked Paul eagerly.

"No," said the shopkeeper. "That was called sarcasm. You can't just wave a magic wand and disappear it. For a start, have you any idea how many different species and classes of demon there are?"

"No," said Paul. "How many?"

Mister Avery looked flustered for a moment. "Lots. Shed-loads, in fact. My point is, you can't just have a generic, get-rid-of-a-demon spell. Stands to reason. There's the type of demon it is, its rank, what subculture it comes from, what the summoning spell was ..."

"Ah, I can help you with that," said Paul, lifting a plastic carrier bag onto the counter. He removed the ancient book, leafed through the brittle pages and showed it to Mister Avery.

Mr Avery looked at Paul, placed a nicotine-stained finger on the page and closed the book on it, all without once glancing at the page. After a pause, and with a sniff of contempt, he picked it up and looked at the spine. He turned it over and examined the back. Finally, he examined the front, so closely that for a moment Paul thought he was going to smell it.

"You can tell a lot about a book from its cover," he said. "Leather-bound, not too sure what animal it came from, but bearing in mind the subject, best not to enquire too closely, eh? Somewhat foxed, but commensurate with its alleged age. Title engraved then inlaid with gilt, though most of it has worn off. Binding is reasonable, no obvious pages falling out." He opened the flyleaf. "Heavy-duty paper, hand-crafted by the feel of it. No printer's name, but that's not unusual for books with a dubious moral message. It was probably a custom run. I'll give you twenty for it."

"Twenty?" echoed Paul.

"Okay, twenty five, but that's my final offer."

"I'm not selling it. That's not why I'm here. I ..." Paul looked around and leant closer. "I used it. I used an invocation from the book, and I summoned a demon, but it's all going wrong and I want to send the little sod back again."

"I see," said Mister Avery, with a voice so level mercury would not roll off it. "You used this book to summon a demon? Let's see, shall we?"

He laid the book back on the counter and opened it where his finger had been keeping his place. "I beseech the powers ..." he read, but Paul interrupted him with a yelp.

"No! Don't read it! Not out loud."

"Do you see any cabalistic sigils drawn on the floor? Have I written the runes of power on my forehead? Is there any evidence of a ram's horn anointed with the blood of a virgin? No? Well, it's not going to matter, then, is it? 'Cos that's what it says you need to have before it'll work. Where'd you find a virgin, by the way? She wasn't local, was she?"

"I just rather you didn't read it out loud, that's all," said Paul, blushing. Finding the virgin was easy. Getting up the courage to cut his own hand had been the difficult bit.

Nevertheless, Mister Avery merely moved his lips silently as he read further. Eventually, he stopped, sucked air through his clenched teeth pensively and looked up.

"Well?" asked Paul.

"What you have here, Sonny, is an invocation to summon a demon from the Pit of Pain."

For a moment Paul was too stunned to say anything. But just for a moment.

"Oh, brilliant! Marvellous! A spell to summon a demon? Well I never. I'd never have guessed."

Mister Avery leant forward on the counter and bared his yellow and uneven teeth. "Don't get shirty with me, Sunshine," he hissed, "or you can just piss off out of my shop, understand? I'm trying to help you here. You're obviously completely out of your depth. Shall we start again?"

"Yes, okay. Sorry," said Paul. "Only, I'm a bit on edge, what with, you know, my problem."

"The point I was making," continued Mister Avery, "was not so much that it was a summoning invocation, but that specifically it was from the Pit of Pain. That gives us a starting point. Your demon isn't going to be more than a level three demon at most. Powerful enough in its way, but not major league stuff. Given that you're a first-time amateur, I'd put money on it being a level one, which would be easy to get rid of. In fact, " he said, turning the page, "it's right here. Did you bother turning the page at all?"

"Yes," said Paul, his voice slow with contained impatience. "I did all that, but it didn't work."

"You must have done it wrong then."

"No. I followed it to the letter ... um ... rune, whatever. It didn't work. Some sort of get-out clause or something. They wouldn't take him back."

"How'd you know you did it right?"

"Because some other guy appeared and told me they weren't taking him back, not even for Mother Theresa's soul."

"What other guy?"

"Lord Roath, he said his name was."

Mister Avery stepped back, nodding to himself. "Lord Roath, eh?" He reached into his pocket and slipped something into his mouth.

"Oh, God, that's bad, isn't it?" said Paul. "What was that? A protection potion?"

"Tic-tac," said Mister Avery absently. "I recognise the name from somewhere. Wait, don't tell me, I'll get there."

Paul wondered how Mister Avery thought Paul would be able to tell him anything.

"First mentioned in Les Betes Diabolique, circa 1520. Had his own cult in France by the turn of the eighteenth century. What does that tell us about him, eh?" he asked Paul, as though Paul should know the answer. Paul shook his head.

"It tells us he's ambitious," continued Mister Avery. "Takes centuries, millennia sometimes, to get your own cult, yet he goes from zero to cult in under two. So, why isn't he mentioned at all in recent grimoires?"

Paul shook his head again, though the old man didn't seem to want an answer.

"Because he's not actively involved in human affairs, that's why. He's a back office boy, working his way up the management ladder. He's a bureaucrat!" Paul marvelled that such venom and contempt could be poured into a single word. "He said you couldn't return your demon?"

"That's right," confirmed Paul. "Exercising their right of refusal, he said."

"Well, if he said he had a right to refuse, he probably has. I know their type, bloody Jobsworths. Know a contract back to front, they do. They think just because they print 'your house may be at risk' on the form, they can take your home from over your head. Bastards!"

Paul suspected the shopkeeper was wandering off track onto some personal path. He tried to steer him back.

"So, I'm stuck with Scarth? There's no way out?"

"I didn't say that, did I? There's always a loophole. No lawyer ever got rich making a good contract. They get rich exploiting loopholes, and who writes them loopholes into the contract in the first place, eh? But first, you got to get your facts right. What sort of demon are you saddled with?"

Paul shrugged. "I don't know. It doesn't come with a label."

"You got yourself a binding invocation there, so it's bound to your will and body. He in the shop now?"

"Yes," said Paul, turning. Scarth was scaling a bookshelf. He stopped guiltily a foot from the top when he saw Paul looking at him. "He's over there."

"Describe him to me," said the shopkeeper.

"I can command him to make himself visible, if you want," said Paul.

"Not possible," said Mister Avery. "A demon bound to an earthly master can't reveal himself. Everyone knows that."

"He's done it before," said Paul. "I have to order him to, but he's done it. To be honest, I don't think he really understands the rules himself. He's a bit simple. Well, more than a bit simple, really. Quite a bit more, in fact."

"Okay," said Mister Avery, cautiously. "Try it."

Paul ordered Scarth to become visible. Mister Avery nodded to himself.

"What's that, then?" he asked, after a moment's perusal of Scarth.

"That's the demon," said Paul, nonplussed.

"Nope. That ain't a demon," said Mister Avery. "Not sure what it is, but it's no demon. No tail, ears like an elephant's, round pupils instead of slits. That's not a demon. I'll show you a demon, shall I?" He shuffled around the counter. Paul was not surprised to see he was wearing threadbare slippers. He pulled a book from a shelf and opened it. "There!" he said, pointing to an engraved page. "That there's a demon. Got a tail, see? Pointy ears, not flaps. Slitty eyes, like a cat's. Does it talk?"

"After a fashion," said Paul.

Mister Avery turned to Scarth. "What are you?"

Scarth turned to Paul, then back to the old man. "Scarth."

"I didn't ask your name, you idiot. What sort of creature are you?"

"Scarth," repeated Scarth.

"Either you're very stupid, or very, very clever," said Mister Avery. "I'm betting on stupid. You know what I think?" he asked, turning to Paul. Paul shook his head. Mister Avery seemed to ask a lot of rhetorical questions. "I think what you've got here is a chimera."

"Oh, right," said Paul, nodding his head. "What's one of them?"

"It's an abomination, that's what it is, and this thing is evidence of why. I think this is what you get when a demon breeds with a sprite. It has all the intelligence and magical powers of a damp sponge. So, it's your slave, then, yes?"

Paul nodded sadly.

"It got you laid yet, then?"

"I beg your pardon?" asked Paul, affronted.

"Oh, don't give me that," said Mister Avery. "First thing a man would ask for, power over women." He leered. "Or men, depending."

"No, he's not got me laid. He's not got me anything. He has a problem understanding anything I tell him to do, and when he does understand, he just hits it. I told him to vacuum the carpet and he just beat the vacuum cleaner up while screaming 'clean'!"

"Does he exhibit any extraordinary powers at all?" asked Mister Avery.

"He can eat." Mister Avery looked unimpressed. "I mean, he can eat and eat. I saw him ..."Paul dropped his voice to barely a whisper. "I saw him swallow a person whole. Bang, and he was gone."

"Yeah?" said Mister Avery, and casually retreated behind the counter. "Well, you got yourself a problem, then, don't you? None of your demonic spells are going to work on him, him not being a demon as such. And no-one has ever written a sprite banishment invocation. No such thing, being as how no-one has needed to before, see? So, you are right up the proverbial creek, Sunshine. I'll give you thirty for the book, seeing as how I feel sorry for you."

"Thirty? That's not going to keep Scarth in ice-cream for a day."

"Ice-cream?" said Scarth, his ears perking up.

Mister Avery shrugged. "Suit yourself, but you're not going to get a better offer anywhere else."

Scarth leapt off the bookshelf and landed on all fours on the counter. "Ice-cream," he said, with an edge of menace to his voice. Before Paul could react, Mister Avery whipped out from under the counter a medallion hanging on a leather thong and held it in front of Scarth's face.

"Ha! Didn't expect that, did you, Dogsbreath? Know what this is? No? This is the seal of Arwen the Bald. Proof against all creatures of the pit. You try it on with me, Sunshine, and I will introduce you to pain that your Lord Roath can only dream of."

Scarth cowered, then leant forward hesitantly. He sniffed the medallion twisting in front of him, then bit it. As Mister Avery looked on in horror, holding the severed thong in his hand, Scarth chewed speculatively and spat tangled bits of metal onto the counter in disgust. Then he slowly turned to the trembling shopkeeper.

"Okay, listen," said Mister Avery in a voice that quavered so much it virtually minimmed. "You want to be rid of him? Okay, maybe there's a way."

"How?" asked Paul.

"Call him off, first."

"Scarth! Come here."

Scarth turned to Paul, gave Mister Avery a final glare, then dropped to the floor.

"You need to find a loophole, see? Find some way of banishing him that they haven't thought about. Only, to do that, you need help."

"From you?" asked Paul.

"No. I mean, I'd like to, but I can't. You need help from someone with power. If it were me, I'd get help from downstairs."

Paul glanced at the crowded stairway. "Downstairs?"

"Yeah. I mean, from another demon, sort of thing. Don't matter what you are, you can't climb a ladder without treading on a few fingers, and demons, well, they ain't exactly known for their forgiving nature. You want to get one of Roath's rivals on your side."

"Sounds dangerous," said Paul.

Mister Avery gave Scarth a frightened look. "Compared to what, exactly?"

Paul nodded slowly. "Okay, if that's what I have to do. Thanks." He picked up his book and returned it to the plastic bag. "Goodbye, Mister Avery."

"Goodbye," said Mister Avery. "Good luck." After the door had closed he added, "Not that there's that much luck in the world."

His right hand automatically reached out for another digestive biscuit. It patted the empty, packet-shaped space on the counter. "Oi!" he called. "Where's my biscuits, you thieving little git?"