Still nothing. He’s really disappeared, just like Lionel Steiner did all those years ago. But he’d never have gone without his car. And he’d at least leave a note for Mum and Dad. And after all the things he said about trust and honesty, there’s no way he’d have left me without saying goodbye.

I turn and walk into the dining room. The chess set is on the table with all the pieces on their squares ready for a game. I look to my left. My heart stops. Granddad’s sitting in his chair in the dark. I wait for him to say something, but his head is back on the cushion and his eyes are closed.

He’s asleep. He hasn’t packed his bags and left after all.

I step towards him with my trophy behind my back. I don’t want to give him a shock, but I have to wake him up to find out the truth. Samson’s collar jangles as he walks through the hallway. I stop. Granddad opens his eyes and blinks in the dark.

‘Ah, there you are, Felix,’ he says, smiling. ‘I’ve been waiting for you for ages, but I must have dropped off.’

‘I-I-I know, Granddad,’ I stammer. ‘I just . . . I was tired and couldn’t get up.’

My trophy digs into my fingers. I thought that this would be the happiest moment, but my head is so mixed up with Stasi and spies that all I want to do is cry. I look down at the ground.

‘Hey!’ Granddad pushes himself out of his chair. ‘It is okay if you lost, as long as you tried your best.’

I shake my head as he walks towards me. ‘No, Granddad,’ I mumble. ‘It’s not that . . . I won.’ I pull my trophy slowly out from behind my back. ‘I won.’

‘You have won!’ Granddad’s face lights up like it’s been hit by the sun. ‘You have won! Felix, I am so proud of you.’ He puts his hand on my shoulder and shakes me. ‘Very proud, but why aren’t you happy? I know,’ he says. ‘It is the adrenalin. It has left you tired like it used to do me. Sometimes after a big game I would sleep for two days.’

I nod like it could be that, but it’s not. I want to say something now, but Granddad’s got the trophy in his hands and is smiling at it like it’s him who’s won.

I force a smile as Granddad walks over to the sofa. ‘Come and sit here,’ he says, tapping the seat beside him. ‘Tell me all about it.’

I want to tell him that I know who he is, but my tongue is as twisted as the thoughts in my head.

I have to say something.

I have to say it now.