Camille let out a low whistle. Beside her, Olympe was tense as a cat, arched and ready to hiss.

‘This is it. This must be him.’

Camille covered her mouth and pushed them back outside.

‘Ada, stay here with Olympe. See what you can find out about the duc’s … studies. Guil, you’re with me. I want to discover the man behind the mutilation.’

Ada closed the chapel door behind her, and she and Olympe were alone in the dissection room. The smell was atrocious. The sweetness of rotting flesh mingled with astringent turpentine, and damp that rose from the floor. Paris in summer was never a pleasant experience, and most dissecting schools closed when neither student nor teacher could face racing to study bodies that would liquefy as they worked. Either the duc had a strong stomach, or he was desperate to keep working, whatever the circumstances.

Living with her father, she’d had her own pomander, filled with nutmeg and orange peel and spices, to brave the streets when he let her out to the opera or other amusements.

Here, she had nothing.

Ada took a deep breath – regretted it – then crossed between the benches to begin searching the scattered books and drawers and papers that had been left in the room.

Olympe didn’t follow.

She stayed by the door, eyes fixed on the two bodies.

‘Are you all right?’

‘Yes. No. I’m not sure.’

‘You don’t have to do this.’

Olympe shuddered, not taking her eyes from the bodies. ‘I keep thinking: if I had died, is this where I would have ended up? Would he slice me open to dissect my heart and liver and brain? Pickle me like a walnut for everyone to study?’

‘You’re free. That’s never going to happen now.’

She pulled her gaze from the corpses to look at Ada. ‘Just because the duc hasn’t done it yet, doesn’t mean this isn’t the fate waiting for me some day. I want to know why he did this to me.’

‘I understand, you know,’ said Ada after a long silence. ‘Not exactly, of course, but my father made choices for me that he had no right to. He didn’t like how close I was to Camille. He thought her family was dangerous, so when Camille and her father were on trial, he locked me in my room. I know it sounds silly when I put it like that – I’m hardly the first daughter to be locked in – but it was such a betrayal. I’d thought of us as inseparable after my mother died when I was ten. When he stopped me being with Camille when she needed me most, it was like meeting a new person who’d been hiding under his skin all along. He didn’t really care what I wanted. He only thought of me as another project to order and direct as he saw fit.’