He was silent for a few seconds. Eventually, he said, ‘I can’t say you’re wrong, because I’ve got nothing solid to back it up. But . . . I don’t know, I’ve never killed anyone, but I doubt killing’s like cooking, where you might do it one way one time and another way another time: today you might microwave your baked beans, tomorrow you might heat them on the hob. I reckon for a lot of killers, there’s only one way they’d ever kill, either because the method’s part of a ritual that’s important to them, or because only that one way feels possible. Someone who’d lose his temper and strangle a woman in anger wouldn’t kill coldly and dispassionately with a gun—take away the heat of the moment and he couldn’t kill at all. A shooter wants to guarantee absolute control. He wouldn’t be able to face something as risky as a strangling, in case his victim overpowered him, or—’

‘Maybe,’ Charlie cut him off. ‘Maybe all this is true of most killers, but there could be one—let’s call him Aidan Seed— who has killed in more than one way. And who says you have to lose your temper to strangle someone? That could be planned, too.’

‘Milward said Seed wasn’t their suspect,’ said Simon. ‘At least admit it’s possible: Trelease killed Crowther either because Seed was spending time with her, or because he’d given her Abberton , or a bit of both. We know Trelease likes to keep her paintings to herself, doesn’t like the idea of other people getting their hands on them. We also know she attacked Ruth Bussey, Seed’s girlfriend—maybe she’s even killed her by now.’

Charlie groaned. ‘You’re going to say Mary Trelease is obsessed with Seed and she’s killing the other women in his life. That’s wild speculation even for you.’

‘Do you think we can assume Adam Sands in Martha Wyers’ novel is Seed?’ Simon asked.

‘Definitely. I phoned Trinity College, Cambridge. Martha Wyers applied for the job there that Aidan got. They met at the interview, like Adam Sands and the fictional version of Martha.’

‘Then I’m right,’ said Simon, as though this were a plain fact. ‘Trelease murdered first Wyers and then Crowther because she saw them as rivals for Seed’s affection. She’ll kill Ruth Bussey for the same reason, if she hasn’t already.’

‘How does Abberton fit in?’ Charlie asked.

‘I don’t know.’

‘And where’s Seed now? You’re saying Trelease made him drive her car somewhere at gunpoint . . .’

‘She’s killed him.’

‘How convenient,’ said Charlie drily. ‘Everyone I mention, you tell me Mary Trelease has killed them. Evidence? None, which is why you’re saying it to me and not to Milward or Kombothekra.’