I don’t know how long I lie there, exhausted but not asleep, my legs twitching and my mind shouting. And that’s the thing about falling asleep – sometimes it can feel a million miles away, but it sneaks up on you without you noticing and your next thought is that it’s light outside, or the alarm is ringing.

My next thought is that there’s a noise above me – a noise that shouldn’t be there. My eyes shoot open. It’s still fully dark, and the inside of the 154 house is quiet, apart from the familiar creak of the pipes, the gurgle of the radiators and the whirr of my CPAP. My phone is plugged in and lying on the desk next to my bed, cos even though I can’t really use it for anything, it’s just wrong not to keep it fully charged. I lean over and touch the screen. It’s 3:59 a.m. As my eyes get used to the dark, I see that my barricade is as I left it, and I start to think I dreamt the noise. Then I hear it again.

It’s a soft scratching, and it’s moving slowly across the roof, like there’s a sloth tiptoeing around up there, its claws scraping over the tiles. I pull down my CPAP mask and prop myself up on my elbows, staring at the ceiling like it’s suddenly going to turn invisible and I’ll be able to see what’s up there. My first thought is that it’s the thing we hid from at the golf course. But why would it be creeping across my roof? It’s moved over my head now and towards the outer wall of the house where my bedroom window looks out over the street. The window. I have it open a lot because Mum keeps the house so hot. Was it shut? Was it locked?

The blind is only half pulled down, cos I never bother closing it properly when I’ll just have to pull it up again in the morning. If you keep it at half, it’s 155 dark enough at night but you get enough light in the morning to get ready. Why give yourself extra work? I consider getting out of bed to make sure the window’s secure, but I think I’m too late. From the scuffing against the guttering, I’d say that whatever was on the roof is now just above my window.

The heat of the house is so thick, it’s like being smothered in a sleeping bag with the opening sealed up. I’m sweating everywhere, the beads of moisture feeling like insects crawling over my skin as they trickle downwards and drop onto the duvet. I remind myself to breathe.