‘The third shop, the one across the road, didn’t last. It closed, then reopened as a record shop. Later still, the two adjacent buildings were joined properly and became one big Rudolphy’s, though the ceilings were as low as they’d always been and the thick beams didn’t help. My brother Edward nearly knocked himself out more than once. There was a girl we’d see in there sometimes, the owners’ daughter. Elise, her name was. Elise Rudolphy. About my age, maybe a couple of years older. Once I was in there on my own flicking through a second-hand book and she came up behind me and said, “You want that, don’t you?” It was Gibbon’s The History of the Decline and Fall of the Roman Empire. There were three volumes – faded red hardbacks – and I was holding the first in my hands. “If you want it, take it,” Elise told me. She had a terrible voice: a drawly half-English, half-American hybrid. The family was from America originally. Both parents had American accents. I said I couldn’t take the book, that it would be stealing, and Elise said, “I dare you. I won’t tell my parents.” Do you know what I did, Sergeant? I took it.’

‘Wow.’ Sam laughed appreciatively.

‘It wasn’t funny, it was a crime. I’d expect you of all people to know the difference, or else what are you doing here?’

‘Well, I … I just thought—’

‘I was sickened by what I’d done, as soon as I got home. Couldn’t look at myself in the mirror. The next day I took the book back to the shop and gave it to Mr Rudolphy. I confessed all, and told him that his daughter had encouraged me to defraud him.’

‘Right.’ Sam was struggling. What was the point of this story? What was he, the audience, supposed to be thinking, and what was he actually thinking? He ought to know the answer at least to the last question, but he didn’t.

‘Mr Rudolphy thanked me for returning the book. My apology seemed to be enough for him, but it wasn’t for me. That day, I made up my mind to become a policeman. And I did.’ Proust nodded vigorously. ‘You don’t see what any of this has to do with Billy and his victims. Only that Rudolphy’s is where Isobel Sturridge claims to work, and she doesn’t work there. She lied. Incidentally, I read the transcript of Sellers’ interview with her and he describes her as having very short brown hair.’

‘So you think she’s Faith Kendell?’