The cacophony of information from the wall was overwhelming, and the accumulated ephemera was rarely less than five layers deep, obscuring most recognisable features. I traced the line of the river upstream until I found Pimlico. Notes on the surface included ‘Monster Tavern’, ‘Millbank Prison – Austr.’ and ‘Dolphin Square sex ring’. These were all scrawled in black and red biro on small Post-its and snippets of notepaper, some no larger than postage stamps. But beneath them was a much larger note, an index card inscribed with fat black marker pen, obviously one of the first things pinned to the wall when the map was new. To read it I had to move other accretions out of the way, revealing the letters one by one. It said: MISTRESS CITY.

‘Bick,’ Pierce said, making me jump. An orange Post-it, its adhesive exhausted, floated to the floor; I saw one or two were already there. ‘Unusual name – as in Bic ballpoints?’

‘With a k,’ I said, realising that Pierce must know the spelling perfectly well, having seen my name in emails. ‘As in Bicker. Or Bickle.’

‘Ha,’ Pierce said – definitely said, spoken, not a laugh. ‘“You talkin’ to me?”’

‘That’s why I’m here.’

‘It’s a pity it’s not Bic like the pens,’ Pierce said. He spoke with his back to me, busy making coffee in a small kitchen through an arch. ‘That would be a good name for a writer. I’m interested in nominative determinism. The idea that your name has power, that it influences what you choose to do in life. You’re, I don’t know, Mr Heal, so you become a doctor.’

Should I be recording this? I wondered. I fumbled one of my digital voice recorders out of my bag, switched it on, and dropped it into the breast pocket of my shirt. ‘Like our mutual friend,’ I said.

Pierce stopped what he had been doing – pouring milk into a little jug – and frowned over his shoulder at me.

‘F.A.Q.,’ I said, surprised he needed prompting. ‘Given that he’s all over the internet.’

‘Aha,’ Pierce said. ‘Well, that doesn’t count. It’s concocted. Francis is his middle name. Eric Francis Quin. He ditched the Eric and added the A in the nineties. The A doesn’t stand for anything.’

‘I didn’t know that,’ I said.

‘Not many people do, I think,’ Pierce said. ‘He doesn’t publicise the fact. I only know ’cause I’ve been to his flat. I saw some post there and asked about it. I think he’s embarrassed by it now. I mean, FAQs are a bit dated. A bit web one-point-oh for Francis. A bit of sleight-of-hand with the facts on some bulletin board twenty years ago and it ends up haunting him like that.’