‘I was going to say Billie Holiday,’ said Dr Kerensa Moore, the psychological profiler who was their guest for the morning. The low turnout was due to her presence, Simon suspected. No one wanted her or believed they needed her; she was an unwelcome gift inflicted on them by the London higher-ups. There would have been between twelve and twenty detectives here if she hadn’t got involved. As it was, there were three from the Culver Valley, two representing the Met on home turf – Dunning and DC Grace Woolston, a woman with chipped green nail polish and two cats that she talked about as if they were people – and a lone James Wing from Bournemouth and Poole.

‘Billy Dead Mates doesn’t work for two reasons,’ Wing said. ‘One: it’s too Little England. No one in America knows what a Billy No Mates is.’

‘They do now, thanks to us,’ said Dunning. ‘The few who are interested, that is.’

‘It makes us look like parochial hicks in the eyes of the rest of the world,’ Wing insisted.

‘Is your new friend serious?’ DI Giles Proust asked Simon, who flinched. The F-word; the very one he didn’t want to hear. In front of Wing, too. Proust – the third and most senior member of the Culver Valley delegation – was a cunning bastard. He seemed always to know the worst thing to say to Simon, and he always said it. Billy’s might be flawed but Proust’s nickname was perfect: the Snowman, inspired by the icy wasteland he had in place of a heart.

‘Are you serious, DC Wing?’ A new friend for Simon, as Proust saw it, was a shiny new victimisation opportunity for him. ‘Are you this murderer’s public relations manager? You’re worried he might not catch on internationally?’

‘I’m worried about how it looks, yes. If we can’t name our serial killers, thinks the New York Times and USA Today, then maybe we can’t catch them.’

‘The New York Times?’ Proust snorted. ‘You’re aiming high. So far one talk show host with a haircut like a bad wig has given Billy a token mention, and one blogger from Dayton, Ohio, has written a ponderous screed – which, in any case, contains an explanation of the nickname: “In Great Britain, a friendless individual is colloquially described as a Billy No Mates.” And all is clear. I see no problem.’

‘My bigger issue is that the name Billy Dead Mates is misleading,’ said Wing.

At the word ‘misleading’, before the explanation, Simon had got it. He’d understood. Everyone else’s blank expressions told him that he was alone. Just him and Wing, who’d thought of it first.

‘Why isn’t it accurate?’ Sam Kombothekra asked.

‘He’s killing pairs of best friends,’ Proust said loudly and slowly. ‘They’re friends, which is synonymous with “mates”. They’re murdered, which is synonymous with “dead”.’