I chose the last remaining cashier over the self-service checkout. She smiled at me and I smiled quickly back. The total came to £19.02 and I gave her a £20 note and the extra two pennies and I got another smile as she handed me the shopping bag with my items and the receipt in it; between us, we managed the whole thing so deftly and humanly, I felt quite reassured. Just before the automatic doors, for a split second I was tempted to go back and ask the cashier if, broadly speaking, she thought everything was going to be okay.

The rain danced on the road and the cars swished past, their lights shimmering in yellow and red on the wet tarmac. I hung the carrier bag from my wrist, put my umbrella up in one smooth movement, and stepped out resolutely onto the pavement. Cold droplets bounced upward, beading my tights. I hurried on. Up ahead, something fell down in front of one of the streetlamps, a fairly large item and heavy, since it fell so fast. I heard a man cry out, a rough shout of fear, and then I saw another person run across the road in front of a car.

I could not tell what had happened, but my instinct, honed by years of living in London, was to turn on my heel and find an alternative route home. Man run amok at Waterloo? Then I’ll take the Northern Line via Bank. As I hesitated, a small crowd drew up around something. All of a sudden, the situation, like one of those pictures of a platter of fruit and vegetables that turns out to be a man’s face, resolved itself. Someone, or something, had fallen from the roof. If it was a something, it had hit a someone. Someone was on the ground.

I cried out, “Peter!” I think I cried it out more than once. A charge volted through me from the roots of my hair to my fingernails. Peter was lost. Peter might be hurt. Where was Peter? I wanted Peter.

I barged my way forward and knelt. It was a man, a man in a beautiful navy-blue cashmere coat. There was quite a big pool of blood. The rain was falling upon it. I reached out a hand and touched the man’s hair. It was dark, but it was not Peter’s hair.

“Don’t touch him,” someone said. “You’re not supposed to—”

“He’s dead,” I said.

“But you have to wait. You can’t move them. An ambulance is coming.”

“Do you know him then?” A woman this time.

“No.” I stood up.

One of the men was looking upward. “He came off the top,” he said. “And he came all the way down.” He was a big, bald man. He spoke almost with reverence. There was the approaching throb of a siren.