‘Go on,’ Maria urged in a whisper.

‘You all looked so perfect from the outside. Or you did at first. But Bonnie – she looked nothing like the other two, I could see that straight away. And the more I watched her the more I realised she was an outcast. I knew she must be the sister that had been taken from me and I hated that she had all this and I’d been left with nothing.’ She spat out the last word.

‘Only she isn’t the sister that was taken from you,’ Maria said.

‘But when I came over at the start of the summer she latched on to me, telling me all these things like she never felt she belonged here and didn’t feel like part of the family …’ Iona drifted off as Maria caught her breath. She couldn’t bear to hear Bonnie actually felt that way. All the things that had always worried her might be true.

‘I promise you Bonnie is not the girl you’re looking for,’ Maria said.

‘I know,’ Iona replied and Maria was taken aback.

She opened her mouth to ask, how do you know? but the words caught in her throat.

The ensuing silence was unbearable until Iona said, ‘David told me she couldn’t be. He said Bonnie’s mother was only fifteen.’

Maria’s heart leaped into her mouth. She felt her skin turn cold, inch by inch, until her whole body was frozen.

David told her that? He had admitted what they’d done?

‘I know my mum was older than thirteen when she had me, so …’ Iona shrugged. ‘Why did you do it?’ she asked.

Maria couldn’t speak. She wanted to. She wanted to scream that her husband had betrayed them in the worst possible way. He had failed their family. For this girl. This stranger.

Slowly the blood drained from her face.

‘Please tell me why you did it,’ Iona went on. ‘I just need to understand, and then …’ She waved a hand towards the water.

And then you’ll go? Maria thought. And then I’ll get rid of you forever?

‘I’d lost two babies,’ Maria said in a tight whisper. ‘I was worried I wasn’t ever going to have one of my own.’ Her body was rigid with fury. That, she realised, had overtaken fear and now all she could think was that she had to get this girl off the island, but not for Iona’s safety, which David seemed so concerned about – for her family’s.

‘So you thought you’d take someone else’s?’ Iona asked.

‘It wasn’t like that.’ Maria shook her head vigorously. ‘I met her once. I had to. I needed to have some kind of—’ Maria bit her lip. ‘I wanted to reassure myself we were doing the right thing.’

‘You wanted to clear your conscience.’