That I could see it from here was a surprise; that it was still there to be seen, an even greater surprise. Could it really be the same column of smoke, from the same fire? A second giant, skyline-swamping blaze in one week was hardly likely – it must be the same fire, still going after three days. Or was it? I wasn’t sure about its location in the sky, not quite the direction I would expect Barking to be, more to the south …

But the deeper levels of the spine and the gut knew exactly what they were looking at. The plume’s silent movements, that python swelling and squeezing, was just for me now, the menace of the quiet youth in my path who has made full eye contact and is holding it. For a moment I fancied that it had followed me home.

I had to get off this wall. Again, I pulled at the bag, hardest yet, and the branch buckled. Once more I pulled, gripping the wall as tightly as possible, and the branch broke, not cleanly, a nasty diagonal tearing-split that left it attached by a strip of bark. But I had it now. I stopped working on the bag and yanked at the detached section of branch. It tore away without too much effort and I threw it, and the bag, down into the next-door chasm.

Reversing myself along the wall was harder than I imagined. The cold cut the feeling from my hands; the damp made every movement unpleasant. Dizziness was setting in, an after-effect of the vertigo. I wondered if I was about to be sick, and the idea was briefly pleasing – not only a way to purge myself of the curdled remains of last night, but also my way of paying a tribute to next door’s work. Swinging around, I pictured myself falling through the glass roof, into the kitchen, landing on the table among the empty and half-full cans in a snowglobe of shards – I had seen it so many times in movies, always so beautiful, often funny, but not something I wanted to try for myself. I imagined bad falls, bad landings, arteries severed, bones snapping like the branch, spinal fluid spilling, paralysis, slow painful death. My numb fingers tightened on the top of the wall.