‘I don’t understand why you’d care enough to tail Aidan Seed to London instead of making your and everyone else’s life easier by following through on the action you’d been assigned,’ said Dunning. ‘That’s something you’ll have to explain to me. A man who’s committed no crime . . .’

‘Hasn’t he? If Gemma Crowther’s dead at midnight and I saw Seed with her at half past nine . . .?’

‘There were thirty-seven people at the meeting at Friends House,’ said Dunning. ‘Unless they’re all lying, not one of them knows the name Aidan Seed. According to them, and to Stephen Elton, Gemma’s partner, she left the meeting with a Len Smith, a social worker from Maida Vale who’d become a good friend of hers.’

‘Does the physical description match Seed’s?’ Simon asked. ‘A social worker from Maida Vale? I take it you’ve had no luck finding him.’

‘I’m told Smith has been attending regularly for several weeks.’

‘There is no Len Smith! It was Seed—he’s your killer. I saw him go into that house with her. Unless one of your witnesses saw him drive away while she was still alive . . .’

‘Neither of them saw you drive away when you say you did,’ Dunning announced with a smug smile—his first. ‘Shortly after half past nine.’

‘I didn’t leave then or they weren’t looking then?’ said Simon angrily. ‘There’s a difference. Ask your witnesses if they saw Seed’s car outside the house. Get a photo of Seed and show it to the Quaker lot—they’ll tell you he’s the man they know as Len Smith.’

Dunning gave him a look he’d used himself many times, on scrotes who wouldn’t talk.

‘You’re not serious?’ said Simon. ‘Me? I’m on your side of the fence. I lock up the killers.’ Proust sat hunched over his desk like a stone effigy, saying nothing.

‘I’m part of a team of twelve,’ said Dunning matter-of-factly. ‘In my team, we stick to our tasking briefs. Different detectives are handling different aspects of the investigation into Gemma Crowther’s death, and guess what? I got you, babe. Which means you and I are going on a little trip to the Big Smoke, and you’re going to elaborate on the story I’ve just heard from your DI about you and Sergeant Charlotte Zailer—who’s also your fiancée, I believe?’

Simon hated the way he said it as if it were somehow questionable, as if his and Charlie’s engagement meant neither of them could be trusted. Babe? Had Dunning called him that, or had he imagined it?

‘. . . your and Sergeant Zailer’s fixation on Aidan Seed, his girlfriend Ruth Bussey and a woman called Mary Trelease.’

‘All people you should be speaking to,’ Simon told him. ‘Are you?’