I clipped on Stan’s lead and we walked back to the meadow, while Natasha told us how they had been walking back from Kenwood House when they came across a young Cavalier King Charles Spaniel shivering alone under the elms. Then she asked us if we wanted a cup of hot chocolate.

I looked at Scout, and Scout looked at me.

‘Yes, please,’ we said.

We walked back to our cars with our dogs on their leads, and I thought that we looked like one of the families who take their dogs on the Heath at the weekend, one of those lucky families. Not perfect, but intact.

At first I thought she was moving out. There were boxes in the hallway of Natasha’s flat, some of them sealed and some of them open, piled high with clothes and sports equipment, and shoeboxes overflowing with old photos. But she was only shipping out her husband’s things.

She brought us our hot chocolate.

‘First time off lead?’ she asked.

‘Yes,’ Scout said. ‘I don’t like it. Off lead is scary. I don’t like it when he can just run away.’

Natasha laughed. It was the first time I had seen her laugh properly, without anything behind it.

‘But you have to let him go,’ she said. ‘You have to give him that freedom. He’s a dog.’

‘I know he’s a dog,’ Scout said. ‘But I don’t like it.’

Stan roamed the perimeter of the flat, sniffing the skirting board. Susan followed him, sniffing his backside. Natasha and Scout followed the pair of them, laughing together.

Some people who don’t have children themselves try too hard. But Natasha wasn’t like that. She was easy and friendly, and I thought I saw her for the first time. This wild girl who wanted to settle down but picked the wrong man. She looked back at me and smiled. They paused at the window, looking across Regent’s Park. Natasha slipped her arm around Scout’s shoulder. My daughter lifted her face to say something.

I sipped my hot chocolate. Hugo Buck had owned a lot of stuff, I thought, looking at the boxes. The two paintings of the empty city were no longer on the wall. I could see them sitting alone in an old champagne box.

I went over and picked one of them up. The style was very familiar to me now. The secret corners of the city, empty of people, changed by twilight. I’d seen it here, I had seen it on the wall of the Jones family home, and I had seen it again in Salman Khan’s office. The abandoned city in soft half-light; London – I took it to be London – as a place of loneliness and shadows and sadness, full of the Sunday morning stillness that James Sutcliffe saw in the world.