When they’d met six months before it had been the start of a brief but intense affair, appearing as she had out of the blue, a welcome distraction from the futile misery of his growing infatuation with Clara. It had been at the opening night of a friend’s photography exhibition, and the attraction he’d felt for the pretty brunette serving behind the bar had been instant and intoxicating.

Soon they were meeting once a week. The sex had been, frankly, the best of his life, but he’d sensed with some relief that she didn’t want the relationship to develop into anything more. At first he’d been hesitant to confide in her about his misery over Clara, but she had been so sweetly sympathetic, so gently encouraging that bit by bit he’d told her of the hopelessness of it all, including his anger at Luke’s one-night stand with Sadie. He’d quickly grown to rely on her steady support, her wise advice.

He noticed that she didn’t like to talk about herself, the questions he asked of her when they first began to meet always gently batted away. She was older than he was and he sensed she had a private life beyond their weekly meet-ups, so he got used to not prying. And anyway, she was such a good listener, there was so much he wanted to tell her about his own unhappiness. ‘Poor Mac,’ she’d say, stroking his hair, kissing his face, pulling him into bed. ‘Poor lovely Mac.’

And then, a revelation, a shock so great, so unexpected, it had knocked the breath from him. They’d been in bed, their naked limbs entwined, and he had just begun drifting into sleep. ‘I have something to tell you,’ she had said. She sat up, her long brown hair spilling over her breasts, her lovely eyes fastened on his face, her shadow thrown huge across the wall behind her.

‘What?’ he’d said sleepily, then smiled. ‘Sounds serious.’

‘It’s about your friend, Luke.’

‘Luke?’ A jolt of surprise. ‘What about him?’ And he’d recall later how he’d felt the first stirrings of unease, like a gust of cold air ruffling his hair, making his scalp prickle.

‘He’s my half-brother,’ she said. ‘Oliver is my father too.’

He’d given a short startled bark of laughter. Because surely it had to be a joke. And then he’d looked into her eyes and realized that it wasn’t. His first thoughts, of course, were that she was quite mad, and he’d felt a pull of disappointment that this lovely woman who’d seemed to understand him so well, who had been such a comfort, was in fact completely insane. And how was he going to disentangle himself from this? What sort of scene would there be? ‘Erm, listen, Hannah, I …’