‘Nothing,’ Paul said to me. The engine started up again and the boat chugged on, cutting a swath of green water. The shoulders and arms and legs of the people were all bare and sunburned, like the fisherman’s. Then the submerged memory flickered again and I jerked my head in pursuit.

This time I had it.

Only two hours ago. I was driving away from Penny’s. My attention was focused on getting to Turnmill Street but out of the corner of my eye, on the opposite side of the road, I caught a glimpse of a man wearing a beige knitted cardigan. It was too hot even to think of wool, let alone wear it. Everyone else in the city was half naked. So I let the brief image, and its associations, fade away before they even printed themselves in my consciousness. But it had been Colin, near his usual bus stop. I was sure of that.

I snatched at Paul’s wrist. I was already running and he pounded in my wake. ‘I’ve thought of something.’

In the house, Evelyn was still crying hysterically. Her mouth was square and wet, and her eyes were squeezed shut. A policewoman was trying to make her drink a cup of tea. Penny was sitting on her chair beside the computer monitor, answering police questions. She had aged twenty years in as many minutes; she looked like a frail old woman.

Names and addresses of our customers were all computerised, but I kept an old-fashioned notebook for my own use in my drawer in the bindery. I dashed across the yard again and took it out, fumbling with the pages. There was an address for Colin, but no telephone number.

It was a long shot. ‘Quick. We can check this ourselves,’ I called to Paul.

He thumbed the pages of the A-Z as I drove. ‘Here it is. Left at the end, straight on, under the railway bridge. Left here. No, wait, it’s one way. Take the next.’

The traffic was thin, for once. The heat and maybe the smell of violence, kept people penned within their own boundaries like Audrey’s animals. It took us only five or six minutes to reach the address in my book.

It was a cheerless, featureless block of flats, concrete-faced with ugly blue-painted slabs beneath the metal windows. The gardens of the gound-floor flats were weed-filled and littered, reminding me of Audrey’s. But Audrey’s was an eyesore in the groomed expanse of Turnmill Street, whereas every one of these looked as if they never had and never would have the opportunity to be anything but squalid and neglected, and barren of all hope.

We dashed past a group of pallid teenage girls and up a flight of stone steps to a first-floor landing. Colin’s door was one of a pair, but his had a metal grille over it. I pressed the bell and then rattled the grille.