She had asked her dad why horrible things could smell good, and he had laughed. Because we’re not always attracted to what’s good for us, he said. That’s one of the things you have to learn to recognize when you get older. Things that look good but aren’t.

How do you know them? she said.

He shrugged. Ask me. I’ll tell you. I’ll make sure you’re safe.

She’d believed him in the way that kids believed their dads, but he hadn’t, not in the end. She was sure that would be one of the things that tortured him most about her disappearance. As a parent she had learned that, although you wanted all kind of things for your children, what you wanted most of all was for them to be safe.

And when they weren’t you couldn’t forgive yourself.

She’d thought a lot about her parents recently. Were they still alive, even? She assumed they were, but she didn’t know. She didn’t know anything about anyone out there. They could be ill, dead, divorced. James could be a famous actor or footballer – well, maybe not, but something that made him happy. She liked to think – hope – that they were as happy as they could be, given what had happened.

And she liked to think she would see them again, sometime. She dreamed about it often, and, when she woke, she wished she could go back into her dream. The only thing that made her open her eyes were her sons. They were here and real and in this world, not her dream world.

She poured the blue liquid in and watched it seep into the sand. It vanished, leaving only a blue stain behind. When she had vanished, she hadn’t even left that. She had disappeared without a trace.

The way it pooled for a moment then seeped away into the sand was mesmeric. Max would be interested to see it. She turned to the mattress to beckon him over.

He wasn’t there.

‘Max?’ she said.

She heard a noise behind her, then his voice.

‘I’m here. Is this juice?’

He was sitting on the floor next to the bath, holding the bottle of bleach. He started to lift it to his lips and she realized two things.

She had left the lid off the bleach.

He was going to drink it.

A different memory came to her. When she was seven or eight she had climbed up on the washing machine, opened the cupboard above it and taken out a large white plastic bottle. It was fascinating; the cap turned and turned but didn’t open. It clicked, but it stayed on.

And then her mum had come in and gasped and snatched it from her.

What are you doing?