So drink had never ranked high on her list of priorities, even if – some nights – it would have been an easy way to go after her son had gone to bed. In those first few years, the house had seemed massive, its rooms empty, the bed as big as a football field. Drinking herself into blackness may not have been the worst thing in the world, even if it didn’t seem like it now.

She washed her face, popped a couple of paracetamol, then wandered into the kitchen. The blinds weren’t twisted all the way shut and, from where she was, she could see across the rooftops to the beach. Out the front of one of the stores down there she could see a huge inflatable skeleton and remembered that today was Halloween. She watched the sea for a moment, moving metronomically, blue and calm, and then the brightness of the sky started to make her eyes sting, the sun pouring in through the slats of the blinds.

Suddenly, the phone started ringing.

She filled a glass full of water, took a long, deep mouthful, and then shuffled across, assuming it would be Ethan. He’d called the day before, to tell her he was thinking about her on her last day at work, and said he’d call her this morning to talk about how it had gone. He’d find it hilarious that she had a hangover.

As she picked up the phone, she saw the machine was still blinking, reminding her that she had a message she hadn’t listened to yet.

‘Jo Kader,’ she muttered.

‘Ah, Detective Kader. Brilliant.’

It was a man, English accent.

‘I’m not a detective any more,’ she said sharply. ‘Who’s this?’

‘Excuse me. Of course. I’ve had my head in this investigation far too long. Let me start again. Ms Kader, my name’s Patrick Perry and I’m hoping you can help me.’

She’d never heard of him.

‘We haven’t met before,’ he went on, ‘although I left a message on your machine yesterday. I’m not sure if you’ve had the chance to listen to it, but it doesn’t matter if not.’ He paused. Jo couldn’t hear anything beside his voice: wherever he was, it was either quiet or deliberately secluded. ‘I live in the UK, but I’m looking into a case that might possibly have a connection to something that you worked on a long time ago.’

‘How did you get my number?’

‘Uh, well, I found a profile of you on the University of California website.’

It was simple, and obvious, and she felt like a fool for asking. She sank another mouthful of water and willed the paracetamol to kick in. The hangover seemed to be getting worse.