“Charming!” Bill-E huffs.

“Mum hit the roof,” Emmet chuckles. “Told Tump Kooniart what she thought of him and to keep out of our way for the rest of the shoot. She complained to Davida, but he’s an agent for several of the actors so there’s not much Davida can do. In an argument, if it’s us or him, she has to take his side. I could be replaced easily, but if Tump walked off and told his gang to follow…”

“Never mind,” Bill-E says encouragingly. “There’s nothing they can do about it now. This is your scene. Go out there, strut your funky stuff, and leave Tump Kooniart and his brats to stew.”

Emmet laughs, then asks if he can run through his lines with us. This time we let him, and say nothing as he makes his customary mistake and grinds to a miserable halt. Then, before he can practise again, his call comes and we have to leave.

Showtime!

This is the first big action shot of the movie, so a large crowd of curious bystanders has gathered. Thanks to modern technology, scenes with monsters aren’t normally interesting to watch being filmed. More often than not, an actor will play out their part against a blue-screen background. The monster effects are added later, using computers.

But Davida wants the demons to look as lifelike as possible, for the action to play realistically. That means taking a less flashy approach than in her other movies, keeping it gritty and believable, using almost no computer effects.

Bill-E and I find a good place to watch, next to Dervish and Juni. The scene’s being filmed on one of the smaller, darker alleys of Slawter. There’s a manhole on the left side of the street, from which the cover has been removed. The demon will spring out of the manhole, grab Emmet and drag him underground.

“This is going to be fun,” Dervish says warmly. “Hardly anyone here has seen the demon costume. I think people will be really scared.”

“Nonsense,” Bill-E says. “How can you be scared of a guy in a monster suit?”

“Trust me,” Dervish grins. “This doesn’t look like a guy in a suit. There are engines and wires within the costume, so it can pull expressions, ooze slime like you wouldn’t believe, even…” He lowers his voice. “It smells.”

“Come again?” Bill-E blinks.

“Emmet doesn’t know this, so don’t say anything, but Davida wants to wring as much genuine terror out of him as she can. So she created a demon-type stench, to throw him off guard. She has a few other tricks up her sleeve too. I feel sorry for the kid—he doesn’t know what’s going to hit him!”

“I don’t think that’s fair,” I mutter. “He’s nervous enough as it is.”

“Don’t worry,” Juni smiles. “We talked it over with his mother. She gave us the all-clear. He’ll enjoy the joke when he recovers. It will make the scene more believable, which will make his acting seem all the more professional. That will stand him in good stead when he’s looking for his next big role.”

I’m a bit worried about Emmet despite Juni’s reassurances. I’d hate if he got so freaked out that he couldn’t finish filming the scene and had to hand the part over to Abe. I can see the moody Master Kooniart standing across from us, with Bo and their fat, leering father, Tump. I wonder if the stench idea was theirs to begin with.

I’d like to warn Emmet, but Davida is talking with him and Salit, explaining the dynamics of the scene. This is where Salit finds Emmet eating their headmaster and realises he’s working for a demon. Emmet starts to give a long speech about how the demons are going to take over the town and why he’s working for them. In the middle of it, his demonic ally pops out of the manhole and makes off with him.

“It’s important you don’t look like you know what’s going to happen,” Davida tells Emmet. “As far as you know, this demon is your best buddy and Salit’s the one in trouble. You’ll hear some rumblings, feel a few tremors. Ignore them and concentrate on your lines.”

“About that,” Emmet cuts in. “I’ve been having a few problems.”

“Oh?” Davida smiles and waits for him to continue.

“It’s the line, ‘At least not much worse than a guy who gives in to temptation and steals a bar of chocolate.’ I know the line, but I keep coming out with ‘badder’ instead of ‘worse’. If it happens, can we do it again straightaway? I’ll try to get it right, but I might…”

Davida holds up a hand. “Emmet, as far as I’m concerned, there’s not one line in the script that isn’t open to negotiation. I should have made that clear earlier. It’s your voice I want to hear, not mine. If ‘badder’ is what comes naturally to you, then ‘badder’ it is.”

“I can change the line?” Emmet gawps.

“Absolutely.”

A big smile works its way across Emmet’s face. Across from us, Abe and the other Kooniarts are glowering. They couldn’t hear the conversation, but they can see the fear fade from Emmet. They’ve lost their chance to bump Abe up the pecking order. I want to thumb my nose at them and stick out my tongue. But that would be childish, so I settle for a smug wink when I catch Bo’s furious eye.

They shoot the early exchanges several times, from a variety of angles. A fake corpse is placed in the alley, close to the manhole cover. Emmet starts the scene crouched over it, pulling bits off and stuffing them in his mouth. He’s so convincing it’s hilarious, and Salit keeps laughing when he comes upon him.

“ ‘Matt!’ ” he cries, calling Emmet by his screen name. “ ‘What are you doing with Mr. Litherland’s nose in your…’ Sorry!” he shouts, doubling over. “I can’t help it! He looks so crazy!”

“Don’t worry,” Davida says, smiling patiently. “We have all night. Keep trying. The joke will wear thin eventually.” She grimaces at a cameraman. “I hope!”

Salit finally gets through his lines without laughing and they move on to the next scene. The cameras and lights are redirected, the make-up artists make sure Salit and Emmet are looking the way they should, Davida has a last few words with Emmet, then they’re ready to go.

“OK, people,” an assistant director yells. “We’re going to try and get this right first time, so we want absolute quiet!”

When everyone settles down, the technicians do their final checks, Davida looks around slowly from one member of the crew to another, then nods. A man calls out the title, scene and take, and snaps the traditional clapperboard shut.

“And… action!” Davida roars.

“ ‘How could you do it?’ ” Salit cries, in his role as Bobby Mint, boy-hero.

“ ‘What?’ ” Emmet protests. “ ‘It’s not as if anyone liked Mr. Litherland.’ ”

“ ‘But he’s human!’ ” Salit cries.

“ ‘He was,’ ” Emmet corrects him. “ ‘He’s yummy for my tummy now!’ ” Emmet rubs his stomach with a sick laugh. “ ‘I’ve always wanted to eat human flesh. I mean, it’s not an obsession or anything. I wouldn’t go out of my way to kill, skin and cook somebody. But I’ve always been curious, wondered what it would taste like. So, when the opportunity dropped into my lap, yeah, I took it. Does that make me a bad person? I don’t think so. At least, not much badder than a guy who gives in to temptation and steals a bar of chocolate. It’s not like I killed him myself.’ ”

“ ‘But you let it happen!’ ” Salit cries. “ ‘You knew about the demon!’ ”

Emmet shrugs. “ ‘What’s done is done. No point crying over spilt milk—or a butchered headmaster.’ ” He holds out a severed, bloodied arm to Salit. “ ‘You should try some, Bobby. You might like it. It…’ ” The ground begins to rumble. A foul stench fills the air. For a second, Emmet falters and his gaze flicks to the open manhole. Then he recovers and continues like a true professional. “ ‘It goes down super sweet, especially if you add a dollop of ketchup. Tastes a bit like—’ ”

That’s when the demon bursts out of the manhole and grabs him.

It happens in a blur and is so fast, so violent, so shocking, that several people in the crowd gasp aloud.