‘Nottingham Prison?’ My mouth falls open. ‘Why on earth would he be going there?’

‘Going where?’ A voice from the doorway makes us both jump.

‘Sergei!’ Amelia exclaims, and stands up. Then she sits down again. All her confidence has evaporated.

‘The back door was wide open,’ he says. ‘You two look very worried. What has happened?’

Amelia and I look at each other.

‘I’d better get going . . .’ Amelia stands up.

‘No – don’t go,’ I say.

‘Sorry, I’ve got to; I told Ma I’d only be an hour. She needs me to look after Spike while she goes up to the boatyard for some spares.’

And in a flash Amelia has gone.

I look at Sergei. The ordinary boy who turns out to have a secret life of crime.

‘Why are you looking at me in this way, Calum?’ He frowns. ‘As if you have not seen me before . . . as if I am a stranger.’

I shake my head, not knowing where to start.

‘Is Amelia upset about something?’ Sergei looks concerned. ‘I hope she is OK.’

‘Yeah, she’s fine,’ I say, glaring at him. ‘She’s just had a bit of a shock. A big shock, actually.’

Sergei sits down and stares at me.

‘You also look as if you have had a bit of a shock, my friend.’

‘Sergei, you can lose the act now. I know where you’ve been going,’ I say, keeping my voice calm and level. ‘I know you’ve been to the prison today and I’m assuming that’s where you’ve been going in the afternoons. There’s no point in denying it.’

The colour drains from his face in an instant, and then flushes back into his cheeks in the form of two little round hot spots.

‘Amelia. She has followed me,’ he growls.

‘Yes, she did,’ I say, hoping I sound more confident than I feel. ‘She had to because you wouldn’t tell me where you were going and I thought it was you who’d been . . .’

He opens his eyes wide.

‘Well, I thought you might have been going to the centre.’

His whole face seems to darken.

‘You thought I was the one causing the damage there?’ He whispers the words, his features squeezing together as if he can’t quite get his head around this fact.

‘No, but . . . I didn’t know, did I? Because you wouldn’t tell me—’

‘I don’t have to tell you where I am going, Calum. It does not mean I am causing the vandal damage.’

I want to correct him to say ‘vandalism’, but from the way he’s looking at me, and the fact I can’t even move on my own yet, I decide against it.

‘And I found the plan you’d drawn of the centre. Why would you do that?’

‘I wondered if you would prefer a building of the Expressions centre instead of The Shard for your birthday, Calum. It was a silly idea but I thought it would encourage you to enter the competition.’ He looks deflated. ‘I showed your father my plan to see if he could help me to build it, but he said you loved The Shard more.’

‘I’m sorry,’ I say. And I mean it. ‘But why are you going to the prison? Who do you know there?’

For a second he frowns harder, and I think he’s going to tell me to mind my own business. But then he kind of shrinks a bit and sits with his elbows on his knees and his head in his hands.

‘Sergei?’ I say gently, and he looks up, tears streaking his pale cheeks.

‘It is my brother Janusz,’ he says softly. ‘He is stuck inside the prison. He has been there a while.’

I’m speechless with shock. I stay quiet and let Sergei tell me in his own time.

‘He came to England a year ago, just before myself and Mama. He had left our little house in search of a better life,’ Sergei explains, looking at his hands. ‘He got a job on a building site and made some friends. One night in the pub some youths set upon his English friend, Robert. They said Robert had been staring at one of their girlfriends.’

His breathing gets faster, more shallow, but I stay quiet.

‘Janusz tried to defend his friend but they would not listen. When one of the men tried to hit Robert with a baseball bat from behind, Janusz pushed him hard, out of the way. The man fell and hit his head on the corner of the metal counter. The police came in a big van and took Janusz away.’

I can’t think what to say.

‘Janusz got convicted of assault and the court gave him a two-year prison sentence. But the English men who attacked Robert stayed free. I ask you, Calum, where is the justice in that?’

‘I-it doesn’t sound like there’s any justice in it at all,’ I stammer, trying to process everything he’s saying.

A crawling sensation starts on my scalp. Does Dad know about Janusz?

I think about the day I heard Sergei and his mum whispering in Polish to each other in the kitchen. What if she has kept it from Dad for some reason?

‘I visit him three times during the week, and Mama goes each weekend. It is making her very sad.’

‘Has she told my dad?’ I ask him. ‘About what happened to Janusz?’

His face goes a bit red and he doesn’t answer for a few seconds.

‘She is going to tell him very soon. It would have been done by now, but of course then Dziadek fell ill and Mama had to go—’

‘She should’ve told Dad before that,’ I say. ‘Before you both moved in. He’s got a right to know about something so serious.’

The crawling sensation has covered my arms and reached my hands now, and I scratch madly at my fingers. Angie seems to really like Dad, but what if she hasn’t said anything about Janusz because she just needed a place to stay that’s near to Nottingham Prison? Then I remember Dad’s dodgy dealings in counterfeit handbags and how he told Sergei and me not to mention his ‘last’ work trip abroad to her.

‘I beg you not to say anything to your father until Mama returns, Calum,’ Sergei says anxiously. He stands up and shakes his hands like they’re wet and he’s trying to air-dry them. ‘She cares very much for your father and she would not want to make him angry.’

‘He probably will be angry,’ I say, scowling at Sergei. ‘I mean, wouldn’t you be? It’s not nice, being lied to.’

I expect him to shrink back at my words but he grows bolder and scowls back.

‘It is not nice being accused of doing the vandal damage, either,’ he snaps. ‘It is not nice that you think this of me, Calum. Why do you never trust anyone to be a good person? Why do you always expect the worst of them, especially if they come from a different country?’

I open my mouth to shout back at him but I don’t actually have anything I can say to defend myself. Angie herself has shown me nothing but kindness, and yet in seconds I have managed to think the worst of her.

I can’t feel angry at Sergei’s words because he’s surprised me into realizing something that’s true: I just don’t trust people.

Mum’s face drifts into my mind. I can’t remember her much because I was so young back then. But I know she left me, and she left Dad, too.

You should be able to trust your own mum when you’re so small. Trust that she’ll be there forever, no matter what.

If your mum can leave you all alone, who is left to trust?

My face feels hot and my leg is banging with pain as if it’s punishing me for being such an idiot. I look at the carpet in front of me and wish it was quicksand so it could just swallow me whole.

Sergei stands up and walks towards me. He looks as if he’s going to slap me round the head or threaten me. There’s nothing I can do about it in this state; maybe I even deserve it.

I steel myself for what’s coming, but he knocks me out in a whole different way. His face softens and he lays his hand on my shoulder.

‘Calum,’ he says simply. ‘You are my friend.’

My chest bucks as I try and hold in a sudden sob that comes from nowhere. I look away and blink furiously before I make a complete fool of myself.

I think of everything Sergei has done for me while I recover from the accident, how he has always forgiven me the awful things I’ve said to him and brushed aside the fact I’ve been part of a group that has mercilessly bullied him at school.

And it’s at that moment that I realize something for the first time.

Sergei Zurakowski is my friend.

He’s probably the best friend I’ve ever had.