In the days that followed, his thoughts kept returning to Hannah. He was surprised how much he missed her; there had been a connection between them, a sympathy, a sense that she was as alone as he was in her own way, that they shared a singular misery, a longing to make peace with something impossible. Since the party he’d found himself brooding on Luke’s selfishness, his undeserved good fortune, more and more. Finally, late one night when he’d been drunk and wretched, he’d texted Hannah. What did you want me to help you with? he wrote.

Her reply had been instant: Can we meet?

At first the plan had sounded so outlandish that he’d refused. ‘Are you joking? No fucking way.’

‘Three days,’ Hannah had said. ‘It’s only three days. Long enough to teach Oliver a lesson, that’s all, make him see that I haven’t gone away, that I’ll never go away.’

‘Hannah …’

‘He threw me away, Mac. Like rubbish. He threw me away, and my mother too. She died because of him.’

‘Yes, but …’

‘Listen. You love Clara. Don’t you?’

And he’d looked at her, the only person in the world he’d ever admitted that to. ‘Yes. Yes, I do.’

‘And Luke cheated on her, treated her like shit. The woman you love. Do you really want Clara to stay with him? With Luke out of the way, you could be alone with Clara, let her find out about Sadie, show her how much she means to you.’ Tears had filled her eyes. ‘Please, Mac, please. You’re my only hope, I feel as though I’ll never get closure on this if I don’t do something.’

Mac had thought about the guilt that had been plain to see on Oliver’s face and put his arms around her. ‘It’s OK,’ he said, ‘it’s OK, take it easy.’

‘Look, I’m not going to hurt him. I just want Oliver to admit the truth, jolt him out of his smug little life, make him face up to what he did.’

‘How are you going to get Luke to your flat?’

‘You don’t need to worry about that,’ she’d said. ‘I just need your help with a few things first.’

And he hadn’t asked too much, because he hadn’t really wanted to know. The next night he’d gone round to Clara and Luke’s flat, and while Luke had cooked them dinner, he’d sat with Clara, listening as she talked about the holiday they were saving up for, how wonderful it was now that they were living together. The next morning he had phoned Hannah. ‘OK,’ he’d said. ‘I’m in.’