Was I urging Roy or trying to reassure myself? I switched on my flashlight as I sidled through the gap, beyond which the carpet felt not much less soft than loose earth. Roy’s light followed me before he did, and confirmed a sight that had made me falter. Bella’s long thin footprints were nowhere to be seen. All the prints in the derelict lobby, leading to the reception counter and the stairs and returning to the exit, were my own. “Looks like there’s only ever been one person,” Roy said.

“I can see how it looks.” I shouldn’t have let the trick provoke me so much. “Let’s see what they found,” I said.

Roy swung his light back and forth as we crossed the lobby, and I trained mine on the counter. Long shrouded shapes lurched out of the darkness, roused by his flashlight – tables in the dining-room – and on our other side the beam summoned a solitary vagrant star. However unnaturally displaced a star would be, the depth of the darkness it inhabited seemed equally abnormal, even if it owed half its distance to the mirror behind the bar. “Nobody there,” Roy muttered.

I might have replied if I hadn’t been distracted by another absence. Louder than I would have planned I said “Where’s the book?”

“Christ, dad, you can’t think it’s in here.”

“Not that one,” I said, though I wondered if it could be. “The visitors’ book. It ought to be here.”

Roy stared at the rectangular trace it had left in the grime on the counter, an impression that put me in mind of a grotesquely shallow grave, and then at the footprints on the carpet. “Looks like whoever came in took it,” he said.

I felt sure this was true, but not as he imagined. “Let’s find out where they went,” I said.

I moved fast to the stairs, following my own trail. The beam from Roy’s phone set my pallid shadow prancing on the wall, which our lights rendered even more unstable than the torn wallpaper sagging with dislodged plaster. When we reached the middle floor he swung his light from side to side, and doors opened wide along both corridors. No occupants emerged – just shadows that the light had brought to life – and Roy repeated his formula. “Nobody there.”

I hoped it was unnecessary, although surely accurate. As I climbed to the top floor the carpet yielded underfoot so much I could have thought the boards were rotting too. I waited at the bend in the stairs for Roy to catch up while my shadow mimed restlessness, but he said “Go on” with all the breath he could spare, and I thought he might feel trapped. Halting at the top, I shone my beam along the left-hand corridor. My footprints and the returning set overlapped as they vanished into the dark. “Go on then, dad,” Roy said more edgily than ever.