This is hardly comforting. Her mind teems with questions and worries – it would be a relief to talk them over with Simon, but she has known him for long enough to recognise the professional closure in his face. This man is no longer her ally but ‘Dr Carfax’, who absolutely forbids excitement.

Instead she swallows the last of the tea, tasting nothing but heat, and takes a bite of dry cake. Simon hands her the opiates and she drinks them down as a bitter final course.

‘Now you must go straight to bed.’ He looks as if he could use a long sleep himself. In the firelight, his eyes are bloodshot. ‘Promise me.’

‘I will. But first let me see you out.’

She lights a candle and they leave the parlour to-gether.

A chill breeze rushes in the moment she opens the front door, forcing her to cup a hand around the flame of the candle. The rain has stopped, but its metallic scent lingers. The street lamps cast sulphur pools on the pavements.

It is horrible to think of Simon venturing out there alone, with a murderer on the loose.

‘Be careful, Simon. Walk quickly.’

He bows – a proper bow, one leg slightly behind the other. Even with his girth, he has more grace than the police sergeant.

‘Until tomorrow, Miss Darken.’

Placing his hat upon his head, he turns. Agnes watches him walk away, his shape articulated against the light of the street lamp.

Always ‘Miss Darken’. They have known each other since childhood; he is practically a brother to her, yet still there is this constraint between them.

Damp air sneaks around the abbey and touches her cheek. As the sound of Simon’s footsteps die out, she shuts the door and bolts it.

The walls exhale.

Quietly, she begins to climb the stairs. Straight to bed, Simon said, but practice has taught her she has ten minutes, at least, before the opiates begin to drag.

She must look. Just once.

The doors to Mamma’s and Cedric’s bedchambers are closed. Neither of them makes a sound in their sleep. Avoiding the creaky floorboard, Agnes creeps past the threshold leading to her own cold bed and enters her studio.

It is the only place in the house where the air feels alive. Even at night, lit by the wavering flame of her candle, her workplace emits a sort of radiance. Perhaps it is the brass glow of the various machines and apparatus she has acquired over the course of her labour: a physiognotrace with its long pole and a camera obscura amongst them. They were necessary purchases. The modern public want machines, not people: something more like a daguerreotype.

Agnes does not see the appeal. A copper plate, a bit of mercury and they call it art. She is one of a dying breed who would rather have something drawn with soft pencils, or painted lovingly with the stroke of a brush.