“Look. Natasha was a mistake. A small, insignificant mistake that anyone might have made. It was over before it began. Now I’ll probably have to explain it to Lauren, and she’ll think the worst, obviously. As if that’s not enough, here you are insisting that her paranoia is real. Do you think that’s going to help her?”

“I’m sorry, I’m just trying to find the person who did this.”

“It was obvious from the start that it was my wife. Anyone could see that, looking at her medical history, and what happened just after the boys were born.”

“What medical history?”

“She’s been medicated, in the past, for depression. When her mother died she went into a slump for a while. Apart from her father, who she’s never been close to, and a grandmother in Scotland, I’m the only person she has left in the world. So it’s important that she trusts me, especially when she’s unwell. Those hallucinations she had in the hospital, she was confusing dreams with reality. Then you come along and start taking her at her word—well, it only made her think that her delusion was real when really, she should have been accepting that it was not, and concentrating on getting better.”

Harper was confused. “Why are you so angry? Is it because your affair was almost revealed to your wife? Because, not that it’s any of my business, I was careful to make sure it wasn’t.”

“It wasn’t an affair, I told you, it was a … friendship gone wrong. The girl got the wrong idea. She’s got all these issues that I didn’t know about, that I couldn’t deal with then and that I certainly do not want to have to deal with now. It’s complicated, and I don’t want to have to try to explain that to Lauren while she is in the midst of a psychotic breakdown. Surely you can understand that?”

“Look, it’s up to you what you tell your wife, I—”

Harper looked down and drew in a shocked breath. There, inside the house to the side of the doorway were a pair of green high heels that she’d seen before, many times. She thought, no, of course not, that’s ridiculous, but then she inhaled a trace of a familiar scent and she couldn’t prevent herself; she pushed Patrick out of the way and went into the house.

“Hey, what do you think you’re doing?”

Two steps inside and there was Amy, perching in the kitchen, her bare feet wrapped like vines around one leg of the high stool, her hands encircling a coffee mug. No lipstick. Damp hair scraped into a high bun.

“Hello, Joanna,” said Amy, a languid smile developing. “What on earth are you doing here?”