She pictured Mac’s pale, serious face, the small brown eyes that peered distractedly from beneath a mop of black hair.

‘Have you seen Luke?’ she asked.

‘Hang on.’ The White Stripes blared in the background while she waited impatiently, imagining him fighting his way through the chaos of his photographic studio before the noise was abruptly killed and Mac came back on the line. ‘Luke? No. Why? What’s— haven’t you?’

Quickly she explained, her words spilling out in a rush: Luke’s forgotten mobile, his email, his missed interview. ‘Yeah,’ Mac said when she’d finished. ‘That’s odd, right enough. He’d never miss that interview.’ He thought for a moment. ‘I’ll call around everyone. Ask if they’ve seen him. He’s probably been on a bender and overslept, you know what he’s like.’

But his text half an hour later said, No one’s heard from him. I’ll keep trying though, I’m sure he’ll turn up.

She couldn’t shake the feeling something was very wrong. Despite his colleagues’ laughter, she didn’t really think he’d been with another woman. Even if he had, a one-night stand didn’t take this long, surely? She made herself face the real reason for her anxiety: Luke’s ‘stalker’.

Putting the word in inverted commas, treating it all as a bit of a joke, was something Luke had done ever since it had begun nearly a year ago. He’d even christened whomever it was ‘Barry’ – a comical, harmless name to prove just how unthreatened he was by it all. ‘Barry strikes again!’ he’d say, after yet another vicious Facebook message, or silent phone call, or unwelcome ‘gift’ through the post.

But then things had got weirder. First an envelope stuffed with photographs had been pushed through their door. Each one was of Luke and showed him doing the most mundane of things – queuing at a café, or walking to the Tube, or getting into their car. Whoever had taken them had clearly been following him closely – with a wide-angled lens, Mac had said. It had made Clara’s skin crawl. The photos had been stuffed through their letterbox with arrogant nonchalance, as if to say, This is what I can do: look how easy it is. But though she’d been desperate to call the police, Luke wouldn’t hear of it. It was as if he was determined to pretend it wasn’t happening, that it was merely an annoyance that would soon go away. And no matter how much she begged, he wouldn’t budge.