‘Oh no!’ she said. ‘Is she really OK? Hit by a car doesn’t sound good.’

‘I think she managed to jump out of the way just as it hit her. She’s actually fine. The doctor told her it happens more often than you’d think. Has anything like that ever happened to you?’

‘Happily not,’ said Abby.

‘Me neither,’ said Gus when I looked at him.

I filed that away. We already knew that it wasn’t the real Gus in Joe’s day, and this proved it.

‘Do you know what the baby’s going to be?’ said Abby, kissing me on each cheek. ‘Thanks for coming, Ariel. You’re a lifesaver.’

‘It’s a boy,’ I said. ‘It’ll be weird having a boy in the house. Did you find out with the girls?’

God, it was so easy. No wonder adults never seemed to run out of things to say. You lobbed them questions about their babies and children and it went on forever. Even if you didn’t know the person, you could just ask about their children and be instant friends.

‘We did,’ said Abby. ‘I couldn’t bear to know that the technology existed and not use it. A little nephew! How lovely. Right. Coco goes to bed at eight, Zara at eight thirty. They’ll try to get you to read them stories, but don’t let them bully you. Watch TV if you want. There’s biscuits in the tin up there and ice cream in the freezer. Help yourself to anything at all. Tea’s here. Coffee’s here. There’s squash over there, if you prefer. We won’t be later than eleven. I can’t tell you what a relief it is to be able to say, “Got to go – babysitter!”’

And, just like that, they were gone.

We played a few games of hide-and-seek, then I asked the girls to get changed. It was easy. Sasha, I thought, would be a great mother because looking after kids was fun. Coco agreed to go to sleep after five stories, but Zara wanted to talk.

We sat on her bed in her tiny room and I wished with all my heart that I could take her to meet Joe. He would be so happy to see her. Meanwhile being with her was the closest thing I could manage to being with Joe in the real world. I felt a bit psychotic when I admitted to myself that I had leveraged myself into this little girl’s life to try to solve a twenty-year-old mystery, and not because I’d actually wanted to look after her. I’d never had any desire to babysit, had never been remotely interested in children.

That was changing, though. I was enjoying myself.