‘I didn’t think she’d react the way she did when I told her. She was fuming and I realise now that it must have been partly because her own relationship had just ended. She refused to let me try to justify what I was doing and marched off.’

‘And that brings us to the WhatsApp message she sent to you,’ James said. ‘She made it clear that she was going to tell everyone your “sordid secret”, as she put it, and yet you’ve told us that you didn’t try to stop her. And that just doesn’t ring true.’

‘But it is true,’ Libby responded, her voice cracking. ‘We didn’t think she would actually do it. Not to me, her own sister.’

‘But you couldn’t possibly have been sure considering the state she was in. And that’s why it’s hard for me to accept that you didn’t go looking for her.’

‘I’ve already told you that I went straight to the bar and met Greg and Mark. And I stayed with them.’

‘Yes, you were captured on a surveillance camera, Mrs Murphy.’ James turned to Ethan. ‘But you weren’t, Mr Prescott. So, we can’t be sure where you went after Rachel rushed off.’

‘I joined Mum on the terrace. You know that. And I didn’t go back into the garden.’

‘It’s true,’ Claire said. ‘How many times do we have to tell you that?’

‘We can’t just take your word for it,’ James told her. ‘How do we know you’re not just saying it to protect your son?’

‘Because I wouldn’t do it if I thought he’d killed Rachel. That should be bloody obvious.’

‘No, Mrs Prescott. What’s obvious to me is that your son has become our prime suspect. We now know that he had a lot to lose if Rachel revealed what her sister had told her. That gave him a clear motive for wanting to stop her. He also had the opportunity. He was already outside and he knew that she was heading down towards the lake.’

Ethan stood back from the sofa, vigorously shaking his head. ‘No, it wasn’t me. I didn’t go to the jetty and I didn’t kill Rachel.’

At the same time, Libby leapt to her feet and spun round to face him.

‘Please tell me that you’re not lying, Ethan,’ she pleaded. ‘I can’t bear to think that you’re the one who hurt my sister. I would never—’

‘You’ve already asked me that, Libby, and I swore that I didn’t. I thought you believed me.’

Libby squeezed her hands into fists and pushed them against her temples.

‘I did. I mean I do. But now … Oh Jesus, I don’t know what to think anymore.’

Claire reached out, grabbed Libby’s sleeve, and pulled on it.

‘Stop it, Libby. Stop it. You must know in your heart that it wasn’t Ethan.’

James decided it was time to take things to the next level and pile the pressure on their latest prime suspect. They needed to get him back to the station and question him under caution as soon as possible.