We walk back to South Kensington tube station. Exhibition Road is busy. A woman in a pretty dress led by a guide dog walks towards us and there is so little space on the pavement that the dog, in its neon harness, brushes Dad’s leg as he passes. It gives a muffled snort, as they continue on their way, a small elephantine trumpet.

‘A guide dog,’ Dad says, stifling a small sneeze.

‘Yes,’ I reply.

He is quiet for what seems like a very long time.

‘I still miss them.’

‘I know.’

‘I never wanted to have to rely on anyone, Prue.’

‘I know, Dad. Mind the kerb.’ I guide him further over to the right, my heart contracting. This summer. This summer maybe everything we want to say will be said. Dad is talking. Dad is talking to me. We walk and I listen.

‘You know, as soon as I became blind my goal was to qualify for a guide dog,’ he says, smiling sadly into the lowering sun. ‘You have to demonstrate you have sufficient mobility and orientation skills before they’ll give you one, show you can travel safely and independently around the local area. So I practised. Nonna and Papa would take you to school and afterwards I would go out, bumble round the neighbourhood until I could convince the guide dog people I was OK. And then we got Sunny; do you remember her?’

‘Yes, she was gorgeous.’

‘She had a lovely temper. Do you remember how she would jump up to the box at pelican crossings and rest her paws on it to indicate to me where the button was?’

I smile. ‘Yes, I remember.’

‘She saved my life. Well, all three of you girls did. I began to head out with almost nothing to fear. I loved people’s reactions. Knowing they were smiling at Sunny – I could feel a warmth radiating from people, you know? Not like now. The buggers.’ I laugh. ‘When the last dog, Folly, had to go, I … Well, you know there’s a bereavement service now for losing a guide dog …? Not in those days. I just internalized it; I couldn’t talk to anyone. One day, when you were at school, I tried to go out alone again with just a cane but it was a disaster. I became disoriented and panicked. I barked – oh, the irony, Prue – at a woman who tried to help me, who grabbed my arm and tried to lead me off somewhere. I felt awful. I went back home and I couldn’t go out again. I just couldn’t do it. All because of a stupid allergy to dogs.’ He shakes his head. He sounds angry and really Italian. ‘It’s ridiculous and I lost everything I had before. I’m so sorry. I’m sorry you have to lead me around now.’

‘I’m not leading you around. We’re out on a trip!’