‘I’m OK,’ he says, and he stands there and he sighs and he smiles and I place my hand on his upper arm, slipping it under the hem of his T-shirt sleeve and I feel his firm, warm bicep. My lovely Dad.

‘Why have we wasted so much time, Prue?’ he says. ‘Sitting in that flat day after day, when all this life – all this beauty – was out here?’

‘I don’t know, Dad. But we’re out now, aren’t we? We’re here.’

‘Yes, we’re here.’

His hand is still on the pane of glass, as though he is drawing energy from it. He sighs again. ‘I’m scared, Prue.’

‘Why, Dad? Tell me why you are scared.’

‘I’m starting to forget.’

‘Forget …?’

‘What things look like, as I’ve been blind for so long. Objects, things, animals, shapes, even. Types of flowers. Colours. I can remember so many things – numbers of things, mainly, how many steps, things I’ve read, but some shapes now, some colours … I don’t remember how a ship’s mast looks. Or paintings by Monet. Or even clouds. Not really.’

‘Oh, Dad. I’m so sorry; I’m an idiot, I—’

‘It’s not your fault.’ He takes his hand from the glass. ‘Your descriptions are excellent, Prue. But when you say there’s a pigeon on the tube, I simply can’t remember what a “pigeon” looks like. It’s so strange, you know, to say the words but not see them in my head.’ He sighs. ‘For a long time I used to test myself every day. Go through a list of animals, say, in my head, one by one. Dog, cat, wolf, bear, rabbit, guinea pig, killer whale … I did it most days, for a long time. Then other days I forgot. And then I’d think, What was the point? Time is a killer, Prue – it is eroding my memory of all these things in life. Some of these animals don’t exist for me, now, or they blur into one. I don’t think I can see a difference in my head now between a dog and a wolf, for example.’

‘Does it matter, Dad, if you don’t know the difference?’ I say, but I know that it does. To him. ‘I could help you. I could describe those animals to you, explain the differences. Talk about lots of other things. Remind you.’

‘I suppose so. If we carried on going out, if we talked more …’

‘We can, Dad! We are doing that, aren’t we? We’re talking now.’

‘There’s so many things now, though. So many things I have forgotten.’

‘We could try, though. What else can we do but try?’