As I keep moving, following the direction of the noise, I can feel the uneven concrete floor beneath my feet. I’ve stopped wearing the shoes I was left: they’re too uncomfortable, my toes too sore from where they didn’t fit and kept rubbing. When the concrete gets too cold at night, and it can become as chilled as an ice rink, I use one of the blankets to wrap my feet up. I have two blankets now: a second was left for me a few days ago. Maybe a week. I didn’t understand why to start with, but then I could feel it: the air, still and stale as it is, is mutating. The temperature’s dropping.

One of my hands – out in front of me – hits the north wall and I realize I’ve allowed my thoughts to wander and lost count of my footsteps. Refocusing, I pause where I am and listen: this is the part of the room closest to where I think the sound is coming from. For a second it seems to stop, but then I press both hands to the wall, and I stand motionless and silent, and I hear it again. It’s less frequent now, more distant, but it’s here. Readjusting, I begin sidestepping to my right, keeping both hands on the wall. The walls are made from wood – oak, I think – huge, heavy slabs of it that stretch up higher than I can reach. I’m pretty tall, but even on tiptoes I can’t feel the right angle where the walls must eventually meet the ceiling. One day, I tried launching one of the shoes into the space above my head, to see how far the room went up: in the centre, the only sound it made was when it landed on the floor again; at the edges, though, it was different – it hit the top with a brief, dull thump.

That was when I realized the room has a sloped ceiling.