‘But that will make it hard for her to see Billy’s mum. The new man will not understand if she wants to stay in touch with Mrs Greene. He – the new man – will see it as clinging on to the past and he is not going to like it. So she’ll lose contact and the old lady will be left alone. That’s what it will be like, isn’t it?’

‘But that’s what is meant to happen, Edie,’ I said. ‘You are meant to meet someone else.’

But not Billy’s mother, I thought. The world was not big enough to fill the gap in her life.

Edie cursed, and wiped at her eyes with the back of her hand. And then we did not talk about it for a while.

And that was part of the ritual, too.

After a short drive across North London we sat in my car, a box of Milk Tray opened on Edie’s lap as she removed all the chocolates that would be too challenging for her grandmother’s teeth.

‘Doesn’t look too bad, does it?’ she said through a mouthful of Hazelnut Swirl, showing me the box. There were three or four missing chocolates. I nodded approval, my mouth full of Apple Crunch.

‘She’s still got her Strawberry Temptation, Orange Truffle and Caramel Softy,’ Edie said, closing the lid.

We ate our forbidden chocolates in silence and stared out across the gardens of the Golden Years retirement community, Finchley branch. It was set on one of those winding, leafy backgrounds that make parts of North London look almost rural.

The building itself was a small manor house built for some local big shot at the turn of the twentieth century, a city house that dreamed of the countryside. Beyond the net curtains of leaded windows, white-suited nurses drifted like angels. Another nurse in white was walking carefully along a sanded garden path with an elderly woman, arm in arm, both of them laughing. The nurse pulled the old lady’s collar up against the chill.

‘Lil’s settled in?’ I said.

Edie nodded and I could see her relief.

Lil had a corner room on the first floor. The room was tiny – all the rooms at Golden Years were designed for a largely sedentary single person – and Lil was sitting in the room’s only chair while a Filipina nurse in a pristine white uniform changed her bedding. They were laughing together as we walked in and I was struck by the genuine and easy affection between the residents, who were mostly women, and the white-suited staff.

Edie presented her grandmother with the chocolates.

Lil made her selection, ignoring the missing chocolates, and grinned at us through a Strawberry Temptation.

‘My favourite young couple,’ she said, and I felt my face redden.

‘Wow,’ Edie said. ‘Now the old girl’s really gone batty, hasn’t she?’