‘No, actually, I’ve absolutely no idea.’ She sounded bored.

Allison regretted choosing to phone rather than appear on her doorstep with Jo in tow for safety. She’d have liked to have seen Portia’s face, to see if she was as unconcerned as her voice seemed to indicate. ‘You think drugging me and holding me prisoner is something I’m simply going to let pass without doing something?’

‘You’re imagining things, Allison. You came over to ours for lunch, drank way too much, and when I tried to help you to bed to sleep it off, you became quite violent. If I’m being honest, I was quite scared. You were so out of control, you fell down several steps. We did think about calling an ambulance but between us, Stuart and I managed to get you to bed. Honestly, we’d have been poor friends to have allowed you to go home until you were recovered. You were still rambling and out of it, so we had to lock the room for your safety.’

Had Portia and Stuart sat up all night planning what to say, what to do? Worryingly, it was almost believable. It looked as if their game plan was plausible deniability. Perhaps they believed if Allison was going to do anything, she’d have had the police on their doorstep by now. They were rich. Obviously, with their money came an arrogant belief in their ability to wriggle out of every situation.

It firmed Allison’s resolve. ‘Before I tell you what I want, you should know that a letter has been delivered to my solicitor with instructions it was to be opened should anything happened to me.’ She shrugged when she saw Jo raise an eyebrow.

‘You think you’re so damn clever.’ There was a vicious bite to Portia’s words now, the façade of calm cracking. ‘You’ve no proof of anything.’

Allison forced her laugh to sound amused. ‘But then you don’t know what I have, do you?’ She wanted to believe Portia was gripping the phone in fear, wanted to believe that for once, for once in her damn life, Allison finally had the upper hand.

‘You should have changed the mattress, Portia. Really, that was sloppy of you. Or maybe you didn’t think I’d look underneath. Wouldn’t see the stains, the blonde hairs that weren’t mine. The man who rescued me took swabs and samples.’ Allison almost smiled at the look of amazement on Jo’s face and gave her a thumbs up. There was no comment from Portia. It was doubtful if she was giving Stuart a thumbs up. Hopefully she was looking at him in shock. ‘My friend’ – Allison was amazed how easily all the lies tumbled out – ‘is convinced the DNA will be linked to Amy and to other women who have been reported missing.’