There are walls now.

I went to bed at about one last night. I'd been downstairs for hours after writing the last entry. I took out the rest of the bricks, right up to the edges of the opening, then stood there with the flashlight trying to make sense of it.

I still couldn't find a wall. I couldn't see how far the floor went. Somebody would have had to excavate an enormous amount of earth, and for what? Where were the supports? How was the ground above it still holding up? I kept pointing the light upward, expecting to catch a beam or the underside of something. There was nothing I could see.

Eventually I was too tired to keep looking. I left everything where it was and went upstairs.

At about four a noise woke me. The same scrape, but louder and much lower. I felt it through the mattress. I was out of the sleeping bag before I'd properly woken up and nearly fell going through the bedroom door. My head was spinning.

I ran downstairs, switched on the basement light and went straight to the opening.

There were walls behind it.

I could see them before I even picked up the flashlight. Two walls, close together, with the floor between them. A narrow corridor leading away from the basement. I shone the light down it, but couldn't see an end.

I stood there looking from one side to the other. The walls started just beyond the opening. They were close enough that I should have seen them yesterday. I had the light pointed at those exact places. I had my head through the hole.

I went back up a few steps and sat down because I still felt dizzy. Stayed there until my breathing settled, then went over and looked again. The corridor was still there.

I spent the rest of the night upstairs with the bedroom light on. I don't think I slept again. This morning I made coffee and left it on the kitchen table until it was cold.

I've been going over what I did yesterday, trying to find something I've remembered wrong. I know I was tired. But I spent hours looking into that space, and I can't account for what I saw afterward.

I haven't been back down today. Every time I think about checking, I find something else to do. I've washed the same mug twice.

I don't know whether something has changed down there or whether there's something wrong with me.