‘It is okay,’ says Granddad. ‘Doesn’t worry, I told you, we all have to lose to get better.’ He stops the car outside his house. ‘When I was your age I lost my first game to an eight-year-old boy from Pankow, a suburb of East Berlin where I lived. He didn’t even seem to look at the board and his hands moved as quickly as a Venus flytrap, just like this Rich. So we all lose.’ Granddad gives me a kind smile, the same type of smile Grandma gave me when I dropped an ice cream in the park.

‘It’s okay, Granddad,’ I say dejectedly, looking into the footwell. ‘I know you’re only trying to make me feel better. But I’m as rubbish at chess as I am at everything else.’ I pick up my bag.

‘No, this isn’t the case,’ says Granddad. ‘I would not just say things for no reason. And, Felix, one more thing.’ He puts his hand on my bag. I wait for him to say something, but he just looks at me for a long time.

‘What is it, Granddad?’ I ask.

‘We all learn from our mistakes,’ he says slowly.

‘I know, Granddad, you just said.’

‘Yes, but not just chess. I mean what happened that Sunday. When you thought I was a spy.’

‘I know, Granddad,’ I repeat. ‘And it was a mistake and I did say I was sorry.’

‘Yes, you did, but I think I should say sorry too.’

‘It’s okay, Granddad. You don’t have to. I’m just glad we’re playing chess again.’

‘Me too, but I need to tell you something if we’re going to keep playing. We cannot have suspicions about each other. We must have trust if we are to continue.’

‘But I do trust you, Granddad.’

I wait for Granddad to say something else, but he just stares ahead like he’s a world away.

I reach for the door handle.

‘Just sit still a while,’ says Granddad, glancing round the square. ‘It is best I tell you here.’

Granddad watches Mrs Hardy cleaning her windows, then turns his head and watches a man outside number twenty-five strap a little girl into a pushchair.

‘What’s wrong, Granddad?’ I ask. ‘What do you need to tell me?’

‘Why I keep the curtains closed. Why I don’t like the phone.’

‘And why you tear up pieces of paper?’

‘Yes, that too.’ Granddad takes one more look around the square, then leans closer to me. ‘Felix,’ he whispers. ‘It is true – my country was full of spies.’

‘So you are . . . !’ Granddad’s words take my breath away.