The joke doesn't wear thin for Bo. Every day she drags it out, mocking and ridiculing me, keeping the story of my hysterics alive. She tells anyone who'll listen, the other actors, the crew, Davida. Most smile and dismiss it, too busy to bother about such trivial matters. But knowing they know causes me to blush fiercely every time somebody even glances at me.

Emmet never rang back and I'm too shamefaced to call him. I doubt if he'll have heard about my panic attack, but there's no telling how far Bo might have decided to spread the joke.

The person I'm angriest with-apart from myself, for being such an idiot-is Tump Kooniart. I can't blame Bo for wringing such wicked pleasure out of my embarrassment-it would be hard for any kid to ignore such a juicy bit of bait if it fell into their lap. But why was her father sneaking around outside our room? And why didn't he keep his big mouth shut? If Dervish had heard something like this about Bo, he wouldn't have told me.

Tump Kooniart should have kept quiet. He didn't. So now it's payback time!

I spend a lot of hours thinking about ways to get even with Bo's father. Itching powder in his clothes? Rat droppings in his soup? Human droppings in his stew or chocolate ice cream?!? Shave him bald or glue his lips together while he sleeps?

All good stuff, but basic. I want something that'll give him a fright, that I can use to humiliate him. Like, if he's scared of rats, borrow one of the trained rats which are being used in the film, drop it down the back of his shirt when there's a crowd around, laugh my head off as he writhes and screams. But to do that, I'll have to find out more about him and what he's scared of.

So I start shadowing him. I do it when I'm not in class. I don't tell Bill-E. He'd happily join in if he knew what I was up to, but I don't want him getting into trouble if this backfires. Tump Kooniart's a powerful player. If I humble him in public, I might end up being booted off the set. I don't mind that, but there's no need for Bill-E to suffer too.

Tump's easy to follow. Tall and wide, always dressed in a drab brown suit. He walks with a slow waddle, mopping sweat from his forehead with a handkerchief which rarely leaves his hand. He usually talks loudly as he strolls, to himself if no one's with him. He doesn't seem to be able to keep silent, except when a scene is being filmed. I bet he even talks in his sleep. If I was blind, I could probably follow him by sound alone.

I don't learn much about Tump, except he loves to talk and eat. He has a trailer on the western edge of Slawter, separate trailers beside it for Bo and Abe. Three of the biggest trailers on the set. When he's not on the prowl, making sure his actors are happy or pigging out in one of the canteens, he spends most of his time in the trailer. He makes lots of phone calls. There are no personal computers allowed in Slawter-no video mobiles either-so he has to work from a huge Filofax in which he keeps all his contact details and other info. I think about stealing the Filofax and burning it, but that's hardly going to leave him a trembling wreck!

Close to Tump's trailer, nearly a week after I began shadowing him. Waiting for him to emerge, sitting in the shade of another trailer, reading a movie magazine-always plenty of those around. Starting to tire of the detective work. Bo's still annoying me, but her insults have grown stale. Nobody really laughs at her jokes any more. Maybe I should quit this game and forget about vengeance.

Someone knocks on Tump's door. I look up and spot Chuda Sool entering the trailer. I haven't spoken to Chuda since the day of the "demon" attack. I'm sure Bo told him about my hysterics. He must think I'm a right nutter. He might even feel insulted that I didn't believe him when he told me about Nora and Tump.

"Look what the cat dragged in," someone says behind me. I jump, but it's only Bo, on her way back from filming. "Discover any demons today, Grady?"

"No. Discover any new jokes?"

"Don't need them. Not when the old ones are still funny." She flashes her teeth and growls demonically. I yawn and focus on my magazine until she loses interest and goes away. I wait for the sound of her trailer door locking, then get up, angry, sick of hanging around. I could be playing foosball with Bill-E, not sitting here like a third-rate substitute, wasting my-

Tump steps out of his trailer, followed by Chuda Sool. Tump's talking loudly, mopping away busily at his forehead. Chuda never seems to sweat, which is handy-without eyebrows, sweat would flow straight into his eyes. The pair set off in a northerly direction, looking a bit like Laurel and Hardy from the rear. Since I'm here, I decide to follow. But this is the last time. I've had enough.

Tump and Chuda head for the D workshops. The huge warehouse dominates the northern part of Slawter. I haven't spent much time up here-no point, since access to the workshops is strictly prohibited. As Tump and Chuda show their passes to a security guard on the western door-one of four doors leading into the warehouse-I hang back and take a long look at the building.

Three storeys high, 70 or 80 metres wide, maybe 120 metres long. Large, unplastered block walls. A flat roof. No windows. Grey and featureless, apart from a big red D painted on the wall above the door. A small guard's hut to the right of the entrance.

I'd love to have a look inside, at the monster costumes and puppets. A small part of me still believes the demon was real. If I could check out the costumes perhaps it would help convince me of the truth. But hardly anyone is allowed to enter the hallowed halls of the D workshops. Even Dervish has only seen a small section of the complex.

I wait impatiently for Tump and Chuda to come out. Then I figure, stuff them! I'm through with this crap. I decide to find Bill-E and hang out with him for the rest of the afternoon. But before departing, I wander around the warehouse on the off chance that one of the doors is open, its guard asleep in his hut. That won't happen, of course, but I might as well give it a shot while I'm here.

The guard on the southern door studies me suspiciously as I approach. Though he doesn't openly carry any weapons, it wouldn't surprise me if he had a gun hidden on him somewhere. I smile politely and don't stray any closer. Walk to the eastern end and turn left. The door on this side is shut too and although the guard's in his hut, he isn't asleep-I spot him through the window as I walk past, leafing through a magazine with pictures of tanks on the cover.

I reach the northern end and turn left again. The guard here is standing next to the door, leaning against the wall. He smiles as I go past. I think about stopping to chat, maybe try to blag my way inside, but his smile isn't that inviting.

Back to the western end. Heading south, thinking about where Bill-E might be. As I come up to the guard's hut, the door to the workshops opens. I hear Tump's voice and stop behind the hut, where he and Chuda can't see me, to wait until they pass.

"...not going to like it," Tump is booming.

"They're not meant to like it," Chuda replies in a much softer voice.

"But the boy will be hard to keep quiet. They're so close to each other. Maybe we should take them both."

"One will be enough," Chuda says. "Now all we have to..."

Their voices fade. I remain where I am, frowning, wondering who and what they were talking about.

The next day, Kik goes missing.

Kuk turns up for class by himself, looking lost. "Have any of you seen Kik?" he asks, eyes darting around the room as if his twin sister might be hiding behind a desk. "I can't find her. I don't know where she is. Kik? Are you here?"

Miss Jaun sits the agitated Kuk down, tries to soothe his nerves and coaxes the story out of him. It's not complicated. He woke this morning and Kik's bed was empty. He couldn't find her. Their dad wasn't too concerned-said she'd probably gone for a walk-but Kuk smelt a rat immediately.

"We don't go anywhere without telling each other. She wouldn't have slipped out without saying anything."

"Maybe she just needed to be alone for a while," Miss Jaun suggests.

"We don't like being alone," Kuk says, shaking his head vigorously. "Alone is bad. Alone is scary."

When Miss Jaun fails to calm Kuk's nerves, she calls security and asks a guard if he can put the word out to look for Kik. "It's no big deal," she tells him. "We'd just like to know where she is."

Class proceeds as normal, except for Kuk, who fidgets behind his desk, eyes wide and searching, staring out the window. He unnerves the rest of us. Even Bo is discomfited by him and remains quiet, no jokes or digs.

Towards the end of class, Miss Jaun summons the guard again. He says nobody has seen Kik but they're still looking.

I raise a hand. "Have you tried the D workshops?" I ask innocently.

The guard frowns. "She wouldn't be there."

"She might have snuck in."

The guard grins. "Into the D? I don't think so. Even I haven't been inside-I don't have clearance."

"But she might be there," I insist. I'm holding a steel ballpoint pen, gripping it tight, remembering the conversation I overheard yesterday, Tump saying "the boy will be hard to keep quiet".

"I'll check with the guys who were on duty this morning," the guard says, rolling his eyes slightly. "If they've seen her, I'll let you know."

"Thanks."

The guard leaves. Class ends. Kuk hurries out to search for his sister.

"What was that about the D warehouse?" Bill-E asks, hanging back.

"Nothing. I just thought they might not have looked there."

Bill-E squints suspiciously. "I know you too well, Grubbs Grady," he says in a bad Bela Lugosi accent. "You wouldn't have said something like that without a reason. What are you hiding from me?"

I consider telling him what I heard Tump Kooniart say. But I'm still smarting from my previous humiliation. I don't want to reveal my fears, only for Kik to turn up, leaving me looking like a paranoid maniac.

"It's nothing," I say, unclenching my fist to lay my pen down. "Let's..."

Grey liquid drips from my hands on to the table. Bill-E pulls a face. "What's that?" he asks. "It looks like mercury."

I don't reply. I'm staring at the liquid, the last few drops dripping from my fingers, black ink bubbling on my palms. It's the remains of the pen. The steel ballpoint which I was holding.

I melted it.

Night falls. Kik hasn't been seen all day. Kuk's not the only one worried about her now. Her father's frantic. The search has intensified. The security forces have been deployed in earnest. Davida even suspended shooting so everyone could join the search parties and help.

I'm with a group exploring the eastern end of town, going through all the real buildings, checking behind the facades of the fakes. Trying to focus on the search. Trying not to think about the pen and how I melted it. But I can't not think about it. There could be a scientific explanation. But I'm certain the melting had nothing to do with science. It was magic.

I'm not a natural magician. Dervish told me that only one or two real magicians are born every century. There are others like Dervish and Meera Flame-mages-with the potential to perform acts of magic, usually with the aid of spells. I could maybe do that. But I never have. I'm not keen on magic. Plus, there hasn't been time. Dervish was a zombie for more than a year and he's not been up for teaching duties since he recovered.

So how did I melt the pen?

There's only one answer I can think of. When demons enter our universe, they affect the area where they cross. They're creatures of magic and that magic infects the world around them. When my parents were killed, I was able to tap into the magical, demonic energy and use it to escape. I did it again later in the secret cellar, when I fought Artery and Vein.

I think that's happening now. There's magic in the air-the magic of demons.

We don't find Kik. The search concludes after midnight. Everybody turns in. Most people reckon she ran away. The guards say they'll search for her beyond Slawter tomorrow, take Kuk and his father with them.

I haven't told anyone about my fears. No point-I'd only be laughed at. But I can't sit back and do nothing. I have to try to help Kik, assuming she can still be helped. So I track down Dervish. He's been searching with Juni and a few others. Him and Juni aren't an item yet, but they've been spending more and more time together, and she's with him now. He says she's helping him cope with his nightmares, that she's taught him how to control his dreams, to keep the monsters of his subconscious at bay. But I think he's more lustful than grateful-he's practically bathing in that new aftershave now!

I get my story straight before I hit Dervish with it. I say I saw Kik yesterday, near the D workshops. Tell him I think she found a way in, that she's hiding inside, possibly trapped. "Maybe something fell on her. She could be pinned to the floor, crying out for help, nobody around to hear."

Dervish doesn't think she could get in-security's too tight. But Juni says they should check it out. "It's the one place we haven't explored. If she did somehow sneak in and had an accident..."

Neither Juni nor Dervish has the authority to enter the D workshops, so we go to Davida. We find her in her office, discussing the next day's shoot with Chuda Sool. Davida's tired and irritable-the delay has put the company behind schedule. She hears us out, then shakes her head. "We already checked. Grubbs mentioned the D earlier, so the guards who were on duty this morning-and last night-were questioned. They all said they hadn't seen her."

"But they wouldn't have if she snuck in," Dervish presses.

"Impossible," Chuda says and I catch him shooting a glare at me. "There's no way into the D warehouse other than through the doors. We constructed it to be impenetrable."

"But-" Dervish begins.

"No!" Chuda snaps, staring at Dervish directly.

Dervish stares back at Chuda, his pupils widening. Then he smiles and shrugs. "Guess we were wrong."

Chuda nods, his eyes still fixed on Dervish. "I guess you were."

My stomach tenses. It's not like Dervish to back down so easily. Is Chuda controlling Dervish's thoughts? Was I right about the browless assistant director? Is he in league with demonic forces?

Before I can challenge Chuda, Juni speaks up. "We need to search there," she tells Davida. "Or, if you won't allow us in, send in a team of guards and tell them to fine-comb the place. Because if Kik is in there-and a determined child can always find a way in, no matter how tight the security- she might be in trouble. If we ignore that and something bad happens to her..."

Davida sighs. "Chuda, assemble a team of guards and-"

"I think you should oversee this personally, Davida," Juni interrupts. She smiles sweetly at the glowering Chuda. "No offence, Mr. Sool, but you're too convinced the girl isn't there. You might just take a cursory glance around, then quit."

Chuda bristles angrily and squares up to Juni. Before he can start an argument, Davida says, "We'll have no infighting, thank you. Chuda, please assemble a team for me. I'll go with them into the D workshops and make sure every room and cupboard is scoured methodically. Is that acceptable, Miss Swan?"

"Perfect," Juni smiles and we file out. I walk just behind Dervish, studying him carefully, worried about what might be going on inside his head.

We wait outside the warehouse while Davida and the guards search for Kik. Juni is concerned about Dervish. She asks if he feels all right, if he has a headache. She saw it too, the exchange between him and Chuda. I doubt if she understood it the way I did, but she knows-or senses- something isn't right.

It's after 2:30 in the morning when a yawning Davida and her guards emerge. She shakes her head, exasperated. "No sign. We checked everywhere."

"You're sure?" I ask.

Davida doesn't answer. "We'll search the surrounding countryside tomorrow," she tells Juni. "The girl probably had an argument with one of the other children and took off in a huff. Maybe she'll turn up by herself."

I smother a snort. "I doubt it!"

I set the alarm back an hour and sleep in late. Stare at the ceiling when I wake, tired and grumpy, finding it hard to get out of bed. Wondering what to do about Kik. Ideally I'd like to tell Dervish what I heard Tump Kooniart and Chuda Sool saying. Insist that Emmet was butchered by a demon, and Kik...

But I spoke to Emmet. He wasn't killed. Unless...

You can do just about anything with movie technology or magic. Maybe Chuda Sool was also eavesdropping with Tump Kooniart when I told Dervish and Juni my fears. Perhaps he intercepted the call and faked Emmet's voice, using either a mechanical or magical vocal distorter. Difficult-but not impossible.

I grab my trousers from the chair at the foot of my bed, dig my mobile out of the pocket and dial Emmet's number. There's no dial tone at his end. His phone's turned off or he's somewhere without a signal.

I get up, dress and head for class. I think about asking Juni for alternate phone numbers for Emmet and his mum, but she'd probably want to know why I was looking for them now. I don't want to reveal my suspicions to anyone in case I end up a laughing stock again. So, at the end of lessons, I casually ask Miss Jaun if she has Mrs. Eijit's number. I say I've been trying to contact Emmet on his mobile but haven't been able to get through. Miss Jaun searches her list of names, then calls the number out to me. I thank her and dial it as I head for lunch. Dead, like Emmet's. I try his number again-the same as earlier.

It might not mean anything. Then again, it might.

I try the two numbers several times over the course of the day. Not a peep out of either. I dial directory enquiries and get their home number. Ring it, only to find that the line has been disconnected.

One last try. I remember Emmet telling us about his local school. Again I use directory enquiries, then call and ask if I can speak with Emmet Eijit. I say I found his mobile phone and want to return it. The secretary says Emmet's not at school, he's making a film. I say I thought he'd finished and returned. No, she says, he hasn't. I ask if she's sure, if maybe he's back home, just not at school. She says definitely not, she knows his mother.

I stare at my phone a long time after that, certain I've been tricked. Emmet and his mum are still here, along with Kik-but not necessarily alive.

Night. Kik hasn't been found. The search teams return at seven. Kuk and his father aren't with them. The searchers say Mr. Kane and his son have gone home, in case Kik heads there. I groan when I hear that. I hope it's true. I pray that it is. Not just because I don't want Kuk and his dad to be dead-but because if it's a lie, it means the guards who were with them are part of a cover-up. It means it isn't just Chuda Sool and one or two others I have to be wary of. I might not be able to trust anybody in the entire cast and crew.

Filming resumes in the morning. Davida's still worried about the missing Kik (or claims to be-who can I trust?), but life must go on. A film costs a fortune to make. Every day is vital. She can't afford to have her team sitting around idle. So, while a selection of guards took off to search the land around Slawter as the sun rose, the cameras rolled as normal.

They're filming the second big demon scene tonight. No carnage or loss of life this time. It's a scene from the third act, in which a demon appears to Bobby Mint and his friends. It predicts doom, warns them of the destruction to come, then tells them they can't leave, it's too late, they're destined to die, along with everyone they care about and love.

I've lost interest in filming but I have to go watch tonight's shoot, to check out the demon. I've heard it's different to the one that killed Emmet. I wonder if this creature will be real or a model? I know what I'd put my money on!

A large crowd gathers for the shoot, but not as many as at the first demon show. This scene's being shot outside a church, one of the fake buildings in Slawter. In the script, the heroes have gathered inside to discuss the demons and what they can do to alert others to the danger. Those scenes have been filmed-or will be-on an interior set. This scene is set at the end of their debate. They've just come out. As they're heading down the steps, the demon appears out of the church behind them, laughing, saying it's overheard their entire plan.

Davida sets the scene, runs the actors through their paces, makes sure all the cameras and lights are correctly positioned, then takes her seat. Action!

I watch nervously, holding my breath, as Salit Smit and the others spill out of the church, faces bright and determined. There are eight steps down from the doors. As they hit the second from bottom step, laughter echoes from within.

"Poor, foolish humans," the demon crows. Salit and his crew whirl, gasping. "You think you know so much. But, like all mortals, your knowledge of the world is pitiful. It would be amusing, were it not so sad."

I start to shiver at the first syllable. There's no mistaking that voice, the low, mournful tone. I know what's coming next. I'd give anything to be wrong but I know I'm not.

The demon appears, gliding out of the shadows. He's lit perfectly. I hear murmurs of approval from the people around me. They were caught by surprise with Emmet, but they're ready this time, in control of their emotions. Besides, although this demon is more horrific in appearance than the first, he moves so fluidly and gracefully that they have time to appreciate his design, the months of hard work which must have gone into creating him.

"You cannot defeat me or my kind," the demon says, looking from one so-called hero to another, then beyond, to the crowd watching the filming. "We can go anywhere you can and to places where you can't. We see all, hear all, know all. And we will kill all."

A tall demon, pale red skin with lots of cracks in it, from which blood continually oozes. Dark red eyes. No hair or nose. Grey teeth and tongue. A hole where his heart should be, filled with dozens of tiny snakes. Mangled hands at the ends of eight arms. No feet, just fleshy strips dangling from his waist, giving the appearance of thin, misshapen legs. He doesn't touch the floor, but hovers a few centimetres above the ground all the time.

"This is our town now, or soon will be," the demon says. "There is nothing you can do to stop us." His eyes fall on me and he smiles widely. "There is nothing any of you can do-except be slaughtered."

Then he laughs and drifts back into the church. The doors slam shut. A boy in the group of heroes screams. Davida yells, "Cut!"

Everyone pours forward, cheering, congratulating the actors, remarking on how realistic and creepy the demon was, questioning how the effects team got it to hover so believably, what mechanics were involved.

But there were no strings or engines. It wasn't a model or costume. The few doubts I had up to this point vanish. We're in seriously deep trouble. The demon wasn't speaking from a script. His words weren't meant for the fictional characters-but for those of us watching.

There are real demons here. Emmet has been killed, and probably Kik and her relatives too. And it's going to get worse. Because the monster who wowed the crowd a minute ago is the one who killed my parents and sister, who vowed to kill Dervish, Bill-E and me... the majestic, terrible demon master himself... lowly Lord Loss.