It had begun to go horribly, terrifyingly wrong, very quickly. After Luke went missing, Hannah seemed to change overnight. Gone was the hurt and vulnerable woman he thought he knew and in her place was someone very different. After the second day he had phoned her. ‘Is he OK? Are you going to let him go tomorrow like you said? Rose and Oliver are beside themselves, job done, so you can let him go now, right?’

In a new, harsh voice, completely unlike her usual one she’d said, ‘No, don’t be stupid. I need you to do something for me. I need you to tell me everything you know about Rose and Oliver’s movements from now on.’

‘What? How am I supposed to do that?’

‘Find out. Ask Clara. Every time Clara speaks to Rose, every time Rose phones Clara, or the police speak to Rose, or Oliver and Rose come to London, or whatever, you tell me. Got that? Everything, every detail, you tell me.’

‘What if I don’t?’

She’d sighed irritably. ‘Look I’m pretty close to stabbing this whining prick in the face anyway. Jesus Christ but he never lets up. You give me the slightest reason to lose my temper, and I’ll do it. If you want to see him again, I suggest you do as you’re told.’

He’d had no choice. ‘OK, OK, relax, I’ll do it.’

‘Good. Does Luke have any photos of his sister Emily in his flat?’

‘Emily? What’s she got to do with this?’

‘Just answer the question.’

‘Erm, yeah, he mentioned them to me once when he was drunk, said he keeps them in his office at home, but I’ve never seen them. He told me he never looks at them, still too cut up about it, I guess.’

‘OK. You need to go round there and take them.’

‘What? Why?’

‘Just do it. I’ll give you Luke’s keys.’

When he’d tried and failed to find them her fury had been terrifying. ‘Christ you’re useless,’ she’d spat. ‘I’ll find them myself. By the way, are you any good at doctoring photos? Photoshop, that sort of thing, I have some old pictures Emily gave me years ago of her with her family. I want you to replace her face with mine.’

‘Emily?’ he’d said, his unease deepening. ‘You didn’t say you’d met Emily … When? I don’t understand.’

‘Can you do it?’

‘Well yes, but …’

‘Good. Then I’ve got another job for you.’

And things had gone from bad to worse, as he’d realized that what Hannah had passed off as a little trick to scare Oliver, to make her presence known, was far more twisted and sadistic. When she started to meet Clara, he’d almost lost his mind. ‘You need to stop, now,’ he said. ‘You need to stop or I’ll go to the police.’