Dervish is humming when he returns. "Nice people," he says.

"Especially Juni," I note drily.

"Yes." He picks up the disc and looks at it silently.

"What made you change your mind?" I ask.

"I haven't," he says.

"But you're thinking about it, aren't you?"

"Yes. This is probably nothing to worry about, just a filmmaker conjuring up the usual smorgasbord of hysterical fakes. But I got the feeling Davida knows too much for her own good. She wants the film to be realistic. Maybe she plans to dabble where she shouldn't, use old rites that might backfire. I'm a hard man to find. I'm worried that she was able to root me out. It makes me wonder what else she might know."

"So you want to check the plot and demon descriptions, make sure there's nothing dodgy going on?" I ask. Dervish nods. "Except I got the impression you only agreed to think it over when Juni smiled at you."

"Don't be ridiculous!" Dervish protests. "She had nothing to do with it."

But by the strength of his reaction, and the way he storms out of the room in a huff, I'm sure she did!

Having shrugged off my foolish sense of unease, I try convincing Dervish to let me have a look at the disc. I want to know what a David A. Haym film looks like at this early stage. But he refuses and locks himself in his study. Back downstairs, I fall asleep on the couch. Wake some time during the night, cold, shivering. Think about hauling myself up to bed, but I'm too lazy. Instead I grab a few pillows and stack them around me for warmth. Starting to drift off to sleep again when I suddenly snap wide awake.

Dervish is in trouble.

Not sure how I know-gut instinct. I slide off the couch, scattering the pillows, and race upstairs. Dervish isn't in his bedroom or study. Nowhere on the second floor. Or the first. I wind up back on the ground floor. A quick scout-no sign of him. That means he either went out... or down to the cellar.

Before descending, I go to the kitchen and make sure Dervish hasn't broken into the cutlery cupboard and stocked up on knives. Then I head down the stairs, automatic lights flickering on as I hit the bottom steps. The cellar's where Dervish stores his wine. I don't come down here much. Nothing of interest for me.

Listening to the hum of the lights, watching for shadows, trying to pinpoint Dervish's position. After a minute I take the final step and explore the rows of wine racks, fists clenched, anticipating an attack.

I don't find Dervish in the cellar. Search complete, I want to go back upstairs and try the area outside the house. But there's one place still to look. It's the last place I want to try-which makes me suspect that's where Dervish is.

One of the walls houses a secret doorway. I make for that now. It's covered by a giant wine rack, mostly containing normal bottles. But one's a fake. I find it and press hard on the cork with a finger. It sinks in. The rack splits in two and both halves slide away from each other, revealing a dark, narrow corridor.

"Dervish?" I call. My voice echoes back to me, unanswered.

I start down the corridor, breathing raggedly. The halves of the wine rack slide back into place. I'm plunged into darkness. But it's temporary. Moments later, lights flicker on overhead, the glow just strong enough to see by.

The corridor runs to a secret underground cellar. It's where Dervish keeps his most magical and dangerous books, where he goes if he wants to practise magic. It's where we fought Lord Loss all those months ago. Where I almost died.

I come to a thick wooden door with a gold ring for a handle. The door stands ajar and there's a pale light coming from within. "Dervish?" I call again. No answer. I really don't want to go in, but I must.

I push the door all the way open and enter, heart pounding.

A large room. Wooden beams support the ceiling. Many torches set in the walls, but none are lit. A steel cage in one corner, the bones of a deer lying on the floor within. Two broken tables. A third in good repair. Chess pieces, books, charred pages and other bits of debris brushed up against the walls. A stack of weapons close to the rubbish, lined with dust, riddled with cobwebs.

And Dervish, squatting in the middle of the room, a candle in one hand, a book in the other.

I approach cautiously. Freeze when I catch sight of the book. There's a painting of Lord Loss on the cover. Just his face. And it's moving. His awful red eyes are widening, his lips spreading. Dervish is muttering a spell, bending closer to the book. Lord Loss' teeth glint in the light of the candle. His face starts to come off the page, like a 3D image, reaching for Dervish, as though to kiss him.

I hurl myself at Dervish. Knock him over and punch the book from his hand. The candle goes out. We're plunged into darkness. Dervish screams. I hear him scrabbling for the book. I thrash around, find Dervish, throw myself on top and pin him to the floor, yelling at him, keeping him away from the book, calling his name over and over, using all my weight to keep him down.

Finally he stops fighting, pants heavily, then croaks, "Grubbs?" I don't reply. "You're squashing me," he wheezes.

"Are you awake?" I cry.

"Of course. Now get off before..." A pause. "Where are we?

"The secret cellar."

"Damn. What was I...?"

"You had a book about Lord Loss. You were chanting a spell. His face was moving. It looked like he was coming alive-coming through."

"I'm sorry. I... Let's get some light. I'm awake. Honest. You can get off me. I promise."

Warily I slide aside. Dervish gets to his feet. Stumbles to the nearest wall. I hear him rooting through his pockets. Then he strikes a match, finds the nearest candle and sets it aflame. The room lights up. I see the book, lying facedown. No movement.

"Could you have brought him here?" I ask, not taking my eyes off the book.

"No," Dervish says. "But I could have summoned part of his spirit. Given him just enough strength to... hurt me."

"And me?"

"Absolutely not. You were safe. The spirit couldn't have got out of this room."

"But when I came in?"

Dervish says nothing. A guilty silence. Then a deep sigh. "Let's get out of here. There are things we must discuss."

"And the book?" I ask.

"Leave it. It can't do any harm. Not now."

Standing, I stagger out of the room. Dervish follows, leaving the candle burning, shutting the door on the past, trailing me back up the corridor to the safety of the normal world.

"The Disciples fight the Demonata and do what we can to keep them out of our universe."

We're in Dervish's study. We both have mugs of hot chocolate. Sitting facing one another across the main desk.

"We're all magically inclined," Dervish continues. "Not true magicians, but we have talents and abilities-call us mages if you like. In an area of magic-the Demonata's universe, or a place where a demon is crossing-our powers are magnified. We can do things you wouldn't believe. No, scratch that-of course you'd believe. You fought Lord Loss."

"How many Disciples are there?" I ask.

"Twenty-five, thirty. Maybe a few more." Dervish shrugs. "We're loose-knit. Our founder is a guy called Beranabus. He is a true magician, but we don't see a lot of him. He spends most of his time among the Demonata, waging wars the rest of us couldn't dream of winning.

"Beranabus sometimes gives orders, sets one or more of us a specific task. But mostly we do our own thing. That's why I'm not sure of our exact number. There's a core group who keep in touch, track the movements of demons and work together to deal with the threats. But there are others we only see occasionally. In an emergency I guess Beranabus could assemble us all, but in the usual run of things we don't have contact with every member."

"So that's your real job," I say softly. "Fighting demons."

He smiles crookedly. "Don't misinterpret what I'm telling you. This isn't an organisation of crack magical heroes who battle demons every week. There are a few Disciples who've fought the Demonata several times, but most have never gone up against them, or maybe only once or twice."

"Then what do they do?" I frown.

"Travel," he says. "Tour the world, watch for signs of demonic activity, try to prevent crossings. Demons can't swap between universes at will. They need human assistants. Wicked, power-hungry mages who work with them from this side and help them open windows between their realm and ours. Usually there are signs. If you know what to look for, you can stop it before it happens. That's what we do-watch for evidence of a forming window, find the person working for the demon, stop them before it gets out of hand."

"You don't travel around," I note. "Is that because of me?"

"No," Dervish smiles. "I used to travel a lot, but I do most of my work here now, at the command of Beranabus. It s my job to... well, let's not get into that. It's not relevant."

Dervish sips from his mug, looking at me over the rim, awaiting my reaction.

"What happens when a demon crosses?" I ask.

"It depends on the strength of the demon. Most of the truly powerful Demonata can't use windows-they're too big, magically speaking. They need a tunnel to cross-a wider, stronger form of window. They're much more difficult to open. It's been centuries since anyone constructed a tunnel."

"Lord Loss is a demon master," I note. "He crosses."

"He's an exception. We don't know why he can cross when others like him can't. He just can. There are rules where magic's concerned, but those rules can be bent. Anything's possible with magic, even the supposedly and logically impossible.

"The other demons who cross are nowhere near as powerful as Lord Loss," Dervish continues, "We drive back the lesser specimens, but we leave the stronger demons alone and try to limit the damage."

"You let them get away with it?" I cry. "You let them kill?"

Dervish lowers the mug. "It's not as heartless as it sounds. There's far less magic in our universe than theirs. When they cross, they're nowhere near as powerful as they are in their own realm. And most can only stay here for a few minutes. Occasionally a window will remain open longer, for an hour or two, but that's rare. Thankfully. Because if they could cross with all their powers intact, and stay as long as they liked, we'd have been wiped out long ago.

"We stop maybe half of all potential crossings," Dervish goes on. "Which is pretty good when you consider how few of us there are. Although we're only talking six or seven attempts to cross in any given year."

"So three or four get through?" I ask.

"Approximately. We aren't always there when one crosses. When we are..." He sighs. "If it's a weaker demon, we try to drive it back. A single Disciple will engage it, occasionally a pair. We don't like to risk too many in any single venture."

"And when you don't think you can stop it?" I ask quietly.

Dervish looks away. "A demon will normally kill no more then ten or twenty people when it crosses."

"Still!" I protest. "Ten people, Dervish! Ten lives!"

"What do you want us to do?" he snaps. "There are battles we can't win. We do what we can- we can't do any more. We're not bloody superheroes!"

"Sure," I say quickly. "Sorry. I didn't mean to sound critical. I just..."

"I know," he mutters. "When I first heard about the Disciples, I was like you. I didn't want to admit the possibility of defeat or make concessions. But when you see enough people die, you realise life's not like the movies or comics. You can't save everyone. It's not an option."

Dervish falls silent. We never talked much about his past. To be honest, with all the problems I've faced over the last couple of years, I haven't had time to think about anybody else's troubles. But now that I consider it, I realise my uncle must have seen a lot of bad stuff in his time. We got lucky against Lord Loss. We beat him at his own game and walked away relatively unharmed. But Dervish told me there are more failures than successes when humans battle demons. And if he's been around for even a few failures... seen people die like I saw my parents and sister die... had to stand by and let it happen because he didn't have the power to stop it...

"I'm telling you this because of Davida Haym," Dervish says, interrupting my thoughts. "I went through her disc earlier. From the outline it sounds like fun-demons run wild and take over a town-but I don't like it. The few demons she described are very realistic. She mentions rituals you can use to summon them. She's gathered information cleverly but I don't think she knows how dangerous that information is.

"I'm going to accept her offer to work on set as an advisor. I want to make sure she doesn't accidentally summon a demon or supply others with the means to. The chances of that happening are slim, and in the normal run of things I wouldn't bother with her.

"But I need to get away from here for a while." His eyes are dark, haunted. "I haven't been the same since I came back. The nightmares... fear... confusion. Maybe my brain will never properly recover and I'm doomed to live like this until I die. But I'm hoping I can shrug it off. I've been living the quiet life-too quiet. I need something to focus my attention. A challenge. Something to sweep away the cobwebs inside my head."

"But you're protected by spells here," I note. "You might not be safe outside Carcery Vale. Lord Loss..."

"Remember the book in the cellar?" Dervish says. "Unless I dig myself out of this hole, I don't think I'm safe anywhere."

I nod slowly. "How long will you be gone?"

"However long the shoot lasts," Dervish says. "I'll ask Meera to keep an eye on things while I'm away."

"Meera's going to be staying with me?" I ask, not minding the sound of that one little bit-Meera Flame's hot stuff!

"No," Dervish says. "You won't be here either. Unless you object, I want to take you with me. Billy too."

"You want to take us on set?" I yelp.

"Davida said I could," he reminds me. "Well, she didn't mention Billy, but I'm sure that won't be a problem."

"Brilliant!" I gasp, face lighting up. Then doubt crosses my mind. "But why?"

"Two reasons," Dervish says. "One-I need you to look out for me at night, to help me if the nightmares continue." He stops.

"And the second reason?"

"I don't trust Prae Athim and the Lambs. They might pull a fast one if I'm not around."

"You think they'd kidnap Bill-E?"

"It's possible. Right now I want Billy where I can protect him, twenty-four seven. I'll rest easier that way."

"So we're going into the movie business," I laugh.

"Yep." Dervish laughs too. "Crazy, isn't it?" He checks his watch. "Three-thirty in the morning. Ma and Pa Spleen would hit the roof if we phoned Billy at such an ungodly hour." He cocks a wicked eyebrow at me. "Do you want to ring or shall I?"