As she crept into the drawing room she heard her mother’s voice. Maud was speaking clearly and emphatically, as if she wanted to be overheard, and Carla immediately sensed a warning. ‘Please don’t worry,’ she was saying. ‘It’s because you were so excited. We were both excited.’

Joachim’s voice came in reply, low and embarrassed. ‘I feel a fool,’ he said. ‘You only touched me, and it was all over.’

Carla could guess what had happened. She had no experience of it, but girls talked, and nurses’ conversations were brutally detailed. Joachim must have ejaculated prematurely. Frieda had told her that Heinrich had done the same, several times, when they were first together, and had been mortified with embarrassment, though he had soon got over it. It was a sign of nervousness, she said.

The fact that Maud and Joachim’s embraces were over so early created a difficulty for Carla. Joachim would be more alert now, no longer blind and deaf to everything going on around him.

All the same, Maud must be doing her best to keep his back to the doorway. If Carla could just slip in for a second and replace the bag on the chair without being seen by Joachim, they could still get away with it.

Heart pounding, Carla crossed the drawing room and paused at the open door.

Maud said reassuringly: ‘It happens often – the body becomes impatient. It’s nothing.’

Carla put her head around the door.

The two of them were still standing in the same place, still close together. Maud looked past Joachim and saw Carla. She put her hand on Joachim’s cheek, keeping his gaze away from Carla, and said: ‘Kiss me again, and tell me you don’t hate me for this little accident.’

Carla stepped inside.

Joachim said: ‘I need a cigarette.’

As he turned around, Carla stepped back outside.

She waited by the door. Did he have cigarettes in his pocket, or would he look for the new pack in his bag?

The answer came a second later. ‘Where’s my bag?’ he said.

Carla’s heart stopped.

Maud’s voice came clearly. ‘You left it in the drawing room.’

‘No, I didn’t.’

Carla crossed the room, dropped the bag on a chair, and stepped outside. Then she paused on the landing, listening.

She heard them move from the study to the drawing room.

Maud said: ‘There it is, I told you so.’

‘I did not leave it there,’ he said stubbornly. ‘I vowed I would not let it out of my sight. But I did – when I was kissing you.’

‘My darling, you’re upset about what happened between us. Try to relax.’

‘Someone must have come into the room, while I was distracted . . .’

‘How absurd.’

‘I don’t think so.’

‘Let’s sit at the piano, side by side, the way you like to,’ she said, but she was beginning to sound desperate.

‘Who else is in this house?’

Guessing what would happen next, Carla ran down the stairs and into the kitchen. Ada stared at her in alarm, but there was no time to explain.