‘He wouldn’t say.’

‘Did he have his clothes on when he strangled her?’

‘Wouldn’t say.’

Charlie doubted she’d be able to come up with a question Simon wouldn’t have put to Seed. Everything Gibbs would have neglected to ask, Simon would have asked several times over.

‘He answered some questions willingly and in great detail—others, he wouldn’t open his mouth.’

‘His girlfriend was exactly the same,’ said Charlie.

‘I’ve never come across anything like it before.’ Simon shook his head. ‘You know what it’s like normally: people talk or they don’t. Sometimes there’s nothing doing at first, then you twirl them and they spill the lot. Other times they spout crap until you point out to them how they’ve landed themselves in it, at which point they clam up. Aidan Seed: none of the above. It was like he had this . . . this checklist in his head. Two lists: the questions he was allowed to answer and the ones he wasn’t. When I asked him the questions on the first list, he went out of his way to be informative. Like I said, I got every detail of Mary’s appearance, from the tiny caramel-coloured birthmark beneath her lower lip—he actually said “caramel-coloured”—to her small earlobes, her wiry, curly hair, black with the odd strand of silver.’

‘Is she attractive?’ Charlie asked. ‘Don’t look at me like that. I’m not asking if you fancied her. I just wondered.’

‘She’s not pretty,’ said Simon after some thought.

‘But striking? Sexy?’

He shrugged. ‘Dunno.’

Aidan Seed’s not the only one with a list in his mind of questions it’s not safe to answer, thought Charlie. ‘Did he say if he killed her in the bed or moved her body there later?’ she asked, a question she knew would be on Simon’s acceptable list. Is there anything I wouldn’t do to please him? Would I take early retirement and roam the country with a set of golf clubs, wearing dreadful sweaters?

‘She was in the bed when he killed her, he said. But . . . listen to us.’ Simon took a swig of his beer. ‘ “Did he move the body?” If Seed and his girlfriend are mad, we’ve nearly caught them up. What body? Mary Trelease is alive.’

‘You said “the questions he’s allowed to answer”,’ said Charlie. ‘Who’s doing the allowing? Ruth Bussey? She also seemed eager to talk, but only in response to certain prompts. And then I’d ask her something else—in most cases, the obvious next question—and she’d button it. Not a word, not even, “Sorry, I can’t answer that.” ’

‘Could there be a third person involved, someone who’s telling them what they can and can’t say?’

‘Mary Trelease?’ Charlie suggested.

Simon waved the idea away. ‘Why would she tell them both to go to the police and pretend Seed believes he killed her? Why would they go along with it?’ He didn’t wait for an answer, knowing she didn’t have one. ‘Gibbs asked Trelease if she knew an Aidan Seed. She said no, but he thought she was lying. I asked her again today, told her he was a picture-framer, how old he was. She said no. Seemed genuine enough, but then she’d had a day to polish up her act. Seed, though—he wasn’t acting. He feels guilty about something, that’s for sure. Whatever’s in his head, I wouldn’t want it in mine. He kept saying, “I’m a murderer.” Said he’d felt like he was dying himself when his hands were round her neck, the nail of his left thumb pressing into his right thumb . . .’