‘For helping you become a chess champion?’

‘No, for everything.’

Granddad smiles down at me. ‘I am very proud of you, Felix,’ he says. ‘I hope you are proud of yourself.’

‘I am, Granddad,’ I say. ‘I feel great.’

‘And I hope your mum and dad are too.’ Granddad’s eyes start to water.

‘They are,’ I say brightly, trying to cheer him up. ‘Mum says you’ve got to come with us for tea because we’re going to Nando’s to celebrate.’

‘Okay,’ he says. ‘If that’s what you would like.’

‘I would,’ I say. ‘So are we going to have a game now?’

‘Of course . . . But there is something I must do first.’ He nods as he walks past me into the sitting room. I think maybe he needs to rest, or he’s going to pick up the TV remote and check the morning weather in Germany, but he walks straight past his chair and stands in front of the curtains. I think of following him. I want to know more about the Wall, like why they took it down, but I don’t think this is the right time to ask because Granddad has been staring at the curtains for so long it’s like he suddenly wants to be alone.

I put my trophy down gently on the table without making a sound. I think Granddad should have it in his house for one day.

I edge towards the door.

‘You don’t have to go,’ says Granddad like he’s reading my mind.

‘But I thought . . .’

‘No, I do not want to be alone. I have been sitting here alone too long. I miss your grandma, but she would be mad at me for sitting here in the dark for so long.’ Granddad pauses on his heels like he’s a long jumper gathering himself before the jump. Then he steps forward, lifts up his arms and pulls back the curtains. The sunlight bursts in, turning his grey hair white, turning the red walls pink, making pieces of dust sparkle as they float in the middle of the room. He steps back, takes a deep breath, and then another, like he’s stepped outside on a cold winter morning.

I walk forward and stand next to him. As I look up I can’t tell if he’s smiling or squinting in the light. He takes another deep breath like he’s about to say something important. I wait, but all he does is let the breath out as Jake cycles by. He’s nosing at the house so much he’s heading straight for Granddad’s car. For a moment I think he’s going to smash into it, but then he swerves at the last minute. I don’t think Granddad’s even noticed because he’s just staring straight ahead.

‘Granddad,’ I say. ‘What are you thinking about?’