‘In any case,’ Celia continues, ‘I hope you don’t stop breathing before we’ve finished here, because it would rather spoil our plans. We’ve come up with a good solution to the problem of what to do with you.’ She pauses. ‘We’re going to have you commit suicide… because you couldn’t live with the guilt of having killed your sister.’

It takes me a moment to process her words. Suicide. I guessed they were planning something horrific, but to hear her spell it out so baldly turns my skin to ice. All the while, as she’s telling me these terrifying plans, the memories of what happened ten years ago keep hitting me like pieces of jagged shrapnel. Tearing chunks out of my heart.

Celia stands and takes the rope from Malcolm while he manoeuvres a dining chair into position next to me. She holds the rope in two hands, running her thumb back and forth along its surface, stroking it as she continues talking.

‘We’re using a blocking agent because if I’d simply tied you up, you’d have got rope burns and the authorities might have suspected foul play. But this way, unless they do a specific test during the post-mortem – which is highly unlikely – they’ll simply believe that it was a tragic suicide. The downside, of course, is that it probably doesn’t feel very pleasant for you, sitting there paralysed while all this is going on. But it won’t be for too much longer.’

Malcolm steps up onto the chair with a grunt, and I notice that he’s wearing clear plastic bags over his shoes. Celia hands him the rope and it’s then that I see it has a loop at one end – a noose.

The sight of it makes me feel faint, and I will myself to pass out so that I don’t have to live through the horror of them doing this to me. But although I’m light-headed, I remain stubbornly conscious. And it’s terrifying.

How has my world managed to change so much in the course of a day? Yesterday, I thought my sister was back in Shaftesbury, I was celebrating ten years of marriage to the man I loved, and I believed my in-laws were the wonderful family I had always longed for. Today, I’m processing the fact that my sister was murdered by my husband and has been dead for a decade, and the people I love the most are the ones who betrayed me, lied to me and are now about to kill me.

I’m unable to look up, so all I can see are Malcolm’s legs as he balances on the dining chair. I’m guessing he’s fixing the rope to one of the heavy wooden beams that run across the ceiling.

‘We’d better hope Guy doesn’t come back to check on her,’ he mutters.