It takes a certain kind of person. No one who was afraid of heights would attempt it. No one unfit or unsure on their feet should attempt it. It takes a kind of lawlessness, an unconventional spirit. Claustrophobics are good at it. Some, a very few, are geniuses at it. Wim was, we weren’t. Liv wasn’t, and Jonny, though good, wasn’t in Wim’s class. For us, it was the freedom we could find nowhere else, but once we had pushed ourselves to the limits of what we could do and experienced it to the full, we wanted it no longer.

This morning I interviewed Lysander Taylor and took him on. He’ll start tomorrow. He can do some of the jobs Darren says are not for me, they’re “beneath me.” Apparently I should be into administration, sitting in our little Camden Town office, managing and directing. When we started on the Paddington Basin contract I should avoid these tin-pot jobs, putting batteries in clocks and replacing fuses.

“I’ve never once been called out to put a battery in a clock,” I protested.

“You know what I mean. You’re an inverted snob, you are, poking about in these crummy council flats and hobnobbing with riffraff. For instance, this call that’s come in from that Mrs. Clarkson, my sort of brother-in-law can do that. Let her wait. He can do it tomorrow.”

“Mrs. Clarkson?” I said. “Did she ask for me?”

“Of course she did, Clo. You’re the only one of us she knows by name. But that’s no reason for you to come running.”

“Ah, but I used to know her,” I said, ignoring his cast-up eyes. “She’s a figure from my past. Tell me something, Darren. If Lysander’s your sort of brother-in-law, do you have two sort of wives and does that make you a sort of polygamist?”

He gave me a sidelong glance. “She never said what she wanted, just would you drop in when you’ve a moment. Maybe she only wants a chat about old times. Never mind your time’s precious, you’ve got to work for your living.” The look became suspicious, the kind of probing stare you get from the doctor when he thinks you may have jaundice or measles. “What d’you mean, a figure from your past? And don’t, for God’s sake, say ‘just someone I used to know’.”

“Okay, I’ll say it’s none of your business, if you like that better.”

So Liv wanted to see me. I was intrigued. I asked Clare, our part-time receptionist and phone answerer, to give her a ring and say I’d be along at midday. Whatever she wanted to see me about, it wasn’t two-gang dimmer switches this time.