‘Why would anyone do that?’

‘It’s complicated, but basically, she’s crazy. She lost her own baby and now she’s trying to get her hands on Lily, but I won’t let anyone take her from me. You’re going to help me save Lily. Here, you hold her while I warm her milk.’

After that, for a while Christine was preoccupied with comforting the crying baby, but at last Lily was fed and changed and settled.

‘Now give me back my phone,’ Christine said.

‘Listen, I’m not going to stop you calling the police if that’s what you decide to do, but first you have to hear me out. A lot of people have been telling lies about me, and now even the police are involved, but it’s not true what they’re saying. None of it’s true.’

Ella was so adamant that the baby sleeping peacefully in Christine’s arms was called Lily that it was hard not to believe her. The account of a mad woman who had lost her own baby and had convinced the police that Ella had taken her was more difficult to understand. As Ella said, it was complicated. What was clear was that two women were claiming to be the mother of one baby. But nothing else about Ella’s account made sense.

‘The police can do tests to find out who the real mother is,’ Christine said.

‘No, they can’t. Usually they can, but not in this case.’

‘Why not?’

‘Because – because – the woman who’s trying to steal Lily from me is my long lost twin sister. We met after we left school, so you never knew about her. It’s well known that twins often have babies at the same time, so our babies were the same age. When hers died, she went crazy and she’s been telling everyone that Lily’s hers. But because we’re identical, that means the tests can’t tell us apart. She’s always been jealous of me, and since her baby died she’s become unhinged. But she’s very good at hiding her insanity, and now it’s my word against hers. But my twin has – her husband is high up in the police and that’s why they’ve taken her side.’

Ella explained that she had only taken Christine’s money so she could buy them both tickets to London.

‘You didn’t know I’d go with you,’ Christine pointed out.

‘I knew you’d come.’

Just then, the baby stirred in Christine’s arms and she felt tiny fingers clutch at her hand.