‘Thirteen years ago I had a beautiful baby girl and I called her Ashleigh. But I knew she would be an only child. She had to be an only child because immediately after your birth I was sterilised. And I held you in my arms and I looked at your sweet face and I knew that if, by some genetic accident, I’d had twins, you would have a brother to look out for you, to protect you. What would happen to Ashleigh if her parents died? You were going to be alone and growing up in a harsh and dangerous world. That’s when I decided I would make you a brother. And he would learn to love you and protect you and die for you if necessary.’

Maybe because I had been so out of it for so long, Mum didn’t see my slap coming. It stung my palm, made a loud crack and turned her face to the side. She stayed that way a moment and then slowly turned back to look at me.

‘Aiden had to return to what we called his clinic at very regular intervals.’ She carried on as if nothing had happened. ‘In fact, it was my laboratory, and there I made adjustments, to his size obviously, so that he appeared to grow along with you, and to his appearance, so it matched yours. I also had to update his learning algorithms, to ensure he developed mentally as a normal child should. Everything I did in Aiden’s creation had one purpose. To protect you. And he did, Ashleigh. He saved your life.’

My brain wasn’t working very well, but a sudden insight came to me.

‘Aiden,’ I said. ‘AI.’

Mum smiled and I wanted to hit her again. ‘Yes. The name I chose for him was … appropriate, one might say.’

She stood and resumed her pacing. This time I got to my feet. I nearly stumbled, but I wasn’t going to carry on being someone half-in and half-out of this conversation. I needed to think. I needed to understand. I needed to concentrate.