But she couldn’t get the image of Camille’s head, a brown and pink speck in the vast river, out of her mind. Ada was a capable swimmer, her mother had taught her in the warm Martinique sea. Camille, not so much. Ada had once seen her fall into a fountain and panic. A hundred horrible ends lined themselves up like the results of a morbid experiment. Camille drowning in the middle of the city, so close and yet impossible to help. Camille injured, fighting to stay afloat, nearly reaching safety but succumbing at the last moment. Camille swept right out of Paris, through farmland and to the Channel.

But before Al could say anything else, the creak of the stairs had Ada snapping to attention. The door clattered open and she was flying to meet Camille, Guil and a bedraggled, hooded stranger as they tumbled into the room. Ada pulled Camille out of Guil’s grip and kissed her hard on the mouth, gave her a shake, then burst into tears and wrapped her arms around her.

‘Welcome back,’ said Al laconically.

‘What took you so long?’ sniffled Ada into Camille’s shoulder.

‘We had to hide in the Saints-Innocents safe house,’ explained Guil, peeling off his filthy uniform jacket. ‘The city is crawling with soldiers.’

‘Don’t you ever do that again.’

‘I should be saying that to you.’ Camille’s voice was raspy, and colour was high in her cheeks. ‘I told you to create a distraction, not crash into the damn prison.’

She broke off, coughing, spasms wracking her chest. Ada wrapped an arm round her waist to hold her up, rubbing her back as her wheezing slowed to steady breaths.

‘Do we need to send for the doctor?’

Camille’s chest had never been strong, but lately it seemed to be getting worse and worse – and half-drowning wasn’t going to help.

Camille brushed her off. ‘I’m fine. Just full of water.’

‘Hate to break up this charming display of affection,’ said Al, sliding from behind the table and pouring himself another measure of brandy, ‘but what the bloody hell is that?’

He gestured with his glass to the bedraggled girl.

Ada looked over Camille’s shoulder – Olympe Marie de l’Aubespine, she presumed. Only, the girl had pushed back her hood now to reveal a strange grey bruise coiling across her face and hands and neck. Across every bit of exposed skin. And her eyes … they had no whites. They were all inky pupil.

Ada let out an involuntary gasp.

Under their horrified scrutiny, Olympe shrank against the door frame. ‘Where have you taken me? Who are these people?’

Camille disentangled herself from Ada’s arms and led Olympe to one of the threadbare chairs.

‘This is my battalion, they help me rescue people from prison. They’re safe.’

Olympe let herself be led, still watching Ada and Al warily, and perched on the edge of the chair.