Logan checked his notebook. ‘And look at that: they’ve got you down for the last slot in the Sheriff Court schedule.’ It took a bit of effort, but he managed not to smile. ‘Anyone would think they were doing it on purpose.’

‘I’m going to release all my files on Agnes Garfield. If you need me to interpret them, I can do that too. Just please get me out of here.’

Logan didn’t even blink.

Marks scrubbed a hand across his eyes. ‘Look, it’s. . . I know you say Agnes killed her boyfriend, but it’s simply not possible. She worships him, and I don’t mean that in a sloppy romantic clichéd way, I mean she actually worships him. As if he was a god. She believes he’ll make everything better, that he holds the keys to everything she wants and needs out of life.’

‘Yeah, well – he’s lying on his back, in the mortuary, with three hundred and sixty-five stab wounds all over his body. And then she garrotted him.’

‘Agnes is not a killer.’

‘Really? ’ Logan folded his arms. ‘Because I saw her stab a friend of mine this morning, through the chest, with a movie prop. He’s in intensive care. She nearly killed him.’

Marks’s scabby hands trembled up to his temples. ‘She’s. . .’ A deep breath. ‘If she’s not taking her medication, the psychotic episodes will get worse. It’ll be a terrifying time for her, she’ll be operating in a world populated with monsters and witches, good and evil. And she genuinely believes she’s on the side of good. Everything she does will be because she thinks she’s saving people. It’s not her fault.’

‘What did you talk about: when she called after she went missing? ’

‘She came in to see me a couple of times. She was . . . excited. Jubilant even. She was making a difference, doing the Kirk’s work.’

‘And you didn’t tell anyone. You just let her parents worry.’

‘I couldn’t, she made me promise. I have to respect my patients’ wishes.’

Weaselly little shite.

‘Did she tell you she’d killed someone? ’

‘She didn’t kill anyone. She couldn’t. Not unless Anthony Chung told her to.’

Which would make his torture and death one of the most half-witted suicides on record. Goulding was right: Professor Marks was an idiot.

Logan pointed at the mattress. ‘Wait here. I’ll go have a word with the PCSO. Maybe we can get you out of here without being hauled up in front of the Sheriff.’

A huge smile broke across Marks’s face, tears glittered in his eyes. ‘Thank you.’

‘But that means you have to come up with something that can help us catch her, before she hurts anyone else.’

A nod. ‘Yes, yes, of course.’

Logan stepped outside and closed the cell door behind him.