My breathing shallows. I put my ear to the crack. There’s no noise.

A dead weight the other side?

My mind is creating all sorts of possibilities now. Hopefully they’re all wrong. It can’t be a body. That’s a ludicrous notion.

I put all my weight behind the door, but my feet slip, so I turn and push my back against it instead. Slowly, the door opens enough for me to squeeze through.

For a split second, I’m relieved. It’s just the coffee table. But then the realisation someone moved it there and blocked the door with it, sinks in. And to do it, they must’ve been on this side – in the lounge or kitchen. Which means they only had three options for getting out again: the lounge window, through the kitchen window or out the back door. I rush to each in turn. There’s no evidence of forced entry – or exit – and the windows are firmly closed. No one could’ve closed them from outside. The key is still in place in the back door. I always lock it and leave the key in; it’s an old habit. But did I forget to actually lock up last night?

Tentatively, I pull the handle down. It is locked. How could someone have moved the table up against the door and then have got out again? My tired brain can’t figure it out.

I ignore the voice screaming inside my head saying: They’re still in here. There’s nowhere for them to hide, so they can’t be. Just as I’m about to walk back into the lounge, I hear a clang. I turn to see the back-door key lying on the floor. I draw a rapid breath. It was only loosely in the lock, as if it had been placed in there carefully, so that someone on the outside could still use a key to lock the door.

Whoever’s coming in and out of my home must have their own set of keys. To the back door and possibly the front too. Who has had access to it to be able to get a duplicate? Me. Nick. Barb. Carl. Davina? The thirteenth viewer? I’m back to the original list of suspects. All of them may have had an opportunity to get a back-door key cut. My focus had been so intent on the front door, I hadn’t been worried enough about ensuring the back-door key was secure as well. I curse my stupidity.

I go into the lounge and heave the table back to the centre of the room before the boys get down. It’s not easy – I’m out of puff doing it. Which makes me think Barb would never have been able to manoeuvre it. Perhaps, then, I can take her back off the list?

Unless there’s more than one person involved.