Maud’s first priority was to make sure he had the document. She was to look at it, say something admiring, then put it down. She would lead Joachim to the piano. Then she would find some pretext – Carla tried not to think what – for taking the young man through the double doors that led from the drawing room into the neighbouring study, a smaller, more intimate room with red velvet curtains and a big, sagging old couch. As soon as they were there, Maud would give the signal.

Because it was hard to know in advance the exact choreography of their movements, there were several possible signals, all of which meant the same thing. The simplest was that she would slam the door loud enough to be heard throughout the house. Alternatively, she would use the bell-push beside the fireplace that sounded a ring in the kitchen, part of the obsolete system for summoning servants. But any other noise would do, they had decided: in desperation she would knock the marble bust of Goethe to the floor or ‘accidentally’ smash a vase.

Carla stepped out of the dining room and stood in the hall, looking up the stairs. There was no sound.

She looked into the kitchen. Ada was washing the iron pot in which she had made the soup, scrubbing with an energy that was undoubtedly fuelled by tension. Carla gave her what she hoped was an encouraging smile. Carla and Maud would have liked to keep this whole affair secret from Ada, not because they did not trust her – quite the contrary, her hostility to the Nazis was fanatical – but because the knowledge made her complicit in treachery, and liable to the most extreme punishment. However, they lived too much together for secrecy to be possible, and Ada knew everything.

Carla faintly heard Maud give a tinkling laugh. She knew that sound. It struck an artificial note, and indicated that she was straining her powers of fascination to the limit.

Did Joachim have the document, or not?

A minute or two later Carla heard the piano. It was undoubtedly Joachim playing. The tune was a simple children’s song about a cat in the snow: ‘A.B.C., Die Katze lief im Schnee’. Carla’s father had sung it to her a hundred times. She felt a lump in her throat now when she thought of that. How dare the Nazis play such songs when they had made orphans of so many children?

The song stopped abruptly in the middle. Something had happened. Carla strained to hear – voices, footsteps, anything – but there was nothing.

A minute went by, then another.

Something had gone wrong – but what?

She looked through the kitchen doorway at Ada, who stopped scrubbing to spread her hands in a gesture that signified: I have no idea.

Carla had to find out.

She went quietly up the stairs, treading noiselessly on the threadbare carpet.

She stood outside the drawing room. Still she could hear nothing: no piano music, no movement, no voices.