I’m tetchy from the moment I wake up.

No, I tell Sergei, I don’t want breakfast.

No, I don’t want a shower or a clean set of clothes. I’ll wear my old tracky bottoms and the ripped T-shirt again.

‘What have you got planned for today then?’ I ask him.

I’m trying to sound casual but I think I might sound nervous and unusually inquisitive.

‘Just the usual things.’ He looks at me. ‘We could build a model together this morning, if you wish?’

My heart blips. What if he doesn’t go out as planned?

‘What about this afternoon?’ I suggest.

‘This morning is better,’ Sergei replies. ‘Later, I have to go out for a short time.’

It looks like everything’s going to plan, after all. Later today Amelia will find out what it is Sergei is up to, where it is he’s going every afternoon. And if it turns out he is responsible for the vandalism at the centre, well, then . . . I’ll have to tell Dad. And Dad will have a duty to tell Shaz and the police. That’s the unavoidable truth.

And then . . . well, I’m not sure. I haven’t really thought what might happen after that.

Sergei and Angie might get deported. The authorities could send them back to Poland, I suppose. Back to a potentially dangerous situation with Sergei’s violent father. That might happen anyway, depending on what happens with Brexit.

I don’t really want to think about all the stuff that could happen in the future.

I squeeze my eyes closed and try to get my thoughts in line again.

If Sergei is the culprit, if he’s damaging the centre, he will have to face the consequences. That’s the way stuff works here. It will be nobody else’s fault but his own. Everything will go back to normal for me and Dad. I’ll get my bedroom back and all my space.

Sergei will take his buildings with him, except for The Shard. He can’t take that because he’s already given it to me as a gift. My mind fills with memories of life before Sergei and Angie came to live here.

The cool silence that hit me like an invisible wall the second I got in after school. Dad’s constant and unchanging expression: mouth down-turned, cheeks sagging, permanent frown. He’d come home from working away all week, heavy on his feet, fast asleep by nine o’clock in front of the TV.

He hasn’t been like that at all since the Zurakowskis arrived. Dad seems more alive, more energized, somehow. He’s always laughing and he’s not staying away from home as much.

But Sergei misses Poland, he’s said so. He has also said, many times, how much he misses his grandad and his school friends. If I focus on that, the heaviness in my heart might start to fade.

Sergei suggests building another model together, but I say I feel too tired.

I can’t concentrate on anything, even my screenplay. I keep thinking about what Amelia will discover when she follows him this afternoon.

Beans on toast for lunch, then Sergei seems to be in the kitchen for ages, cleaning up. At last he comes into the room with his jacket on.

‘Is there anything you need, Calum?’

‘No thanks, I’m good.’

‘OK, I am going out for a while. I will see you soon.’

‘See you later,’ I call.

Soon as the back door closes behind him, I text Amelia.

He’s just left. Where are you?

Amelia’s reply is instant.

Corner of next street. Over and out. A

Very funny. Amelia seems to be treating this as a bit of a joke, and it isn’t.

After that, I don’t hear anything. At all.

I try and read through the first scene of my screenplay, but after the third time of reading the first couple of lines, I give up. I don’t feel anything when I read it . . . It needs to feel – I don’t know – more real. I grab my crutches and manage to stand up again, but I’m still unable to take even a step forward without collapsing down in the chair.

I bite each one of my nails in turn, and I close my eyes to try and take a nap, but of course that proves impossible.

Then I get a text.

On my way back to yours. A

I send three texts back asking stuff like: Did Sergei go to the centre? Where is he now? How long will you be?

Amelia ignores them all.

I have no option but to sit and wait.

I scratch at a mark on the tweedy material that covers the armchair. I go through the first scene of the screenplay again. I bite my already severely bitten fingernails. I look out of the window at the roofs of the houses on the opposite side of the road.

After the longest thirty minutes in history, the back door opens.

‘It’s only me,’ calls Amelia.

This is it. This is where I get to find out what Sergei is up to, where I have to break the bad news to Dad, and then Shaz, and finally to the police. There’ll be no more Sergei and Angie in the flat, just me and Dad again.

‘Hello?!’ Amelia waves her hand in front of my face. ‘Earth to Planet Brooks?’

‘Sorry,’ I say. ‘I was just thinking.’

She sighs and sits down on the settee.

‘So . . .’ I start to babble. ‘Did he go to the centre? Is Sergei breaking the windows?’

Amelia looks at me but her face is blank.

‘Just tell me,’ I snap. ‘What’s he up to?’

‘I don’t know,’ Amelia replies.

‘What do you mean, you don’t know? Did you follow him?’

‘Yes.’

‘Did he see you?’

‘No.’ She rolls her eyes. ‘I even managed to get the same bus as him without being spotted. I’m good at this stuff.’

‘The bus?’

The centre is only five minutes’ walk from here. Where could Sergei be going that involves a bus ride?

Amelia twists and untwists her fingers.

‘I followed him to the Victoria Centre bus station. It was easy to stay hidden cos there were loads of people waiting for the buses. Sergei got on one and went straight upstairs so I sat downstairs, right at the back.’

‘Go on,’ I urge her.

‘We were only on the bus about ten minutes when he comes back downstairs. Luckily a few people got off at his stop so I just stayed well behind them. The schedule screen on the bus said we were in Sherwood.’

‘Sherwood?’

‘Can you stop repeating everything I say?’ Amelia snaps.

‘Sorry.’

Sherwood wasn’t far from here, but it’s not a place I ever have reason to go to.

‘So, he walks up this hill on the main street and I stay well behind. There are lots of shops and people around so it’s not hard to stay hidden.’

‘That’s good,’ I murmur. I’m trying not to rush her but I wish she’d stop dragging the story out.

‘He turns into Perry Road. It’s a really long road and there are fewer people about here so I have to hang right back. But he doesn’t turn around.’

Perry Road. It sounds familiar for some reason, but I’ve never been there.

I stay quiet.

‘Then, at the end of Perry Road, he takes a turn and just disappears.’

‘You lost him?’ I feel a rush of blood to my head.

‘Calm down, Calum; I didn’t lose him!’ She scowls at me. ‘But I can’t see where he’s gone at first because I’m hanging back, remember?’

‘Yeah, course, sorry,’ I mumble.

‘Anyway, when I catch up I see what this place is. I see Sergei pressing a buzzer and waiting at the big gates to be let in.’

‘Did you manage to follow him in?’ I envisage a big house with electric gates. Who does Sergei know who lives in a place like that? He’s never mentioned anyone, but I know there are people around who have made an awful lot of money through criminal activities. Maybe it was the head of some crime syndicate that’s come over here from Eastern Europe.

‘No. I couldn’t follow him,’ Amelia says slowly.

I throw my hands up in frustration.

‘I couldn’t follow him in because he went into the prison,’ Amelia whispers. ‘They opened the doors for him and he walked right in there.’