‘The first time I sat on this bench, my feet didn’t reach the floor,’ Carla said.

Frieda said: ‘I wish we could go back to those days.’

It was a sultry afternoon, overcast and humid, and they both wore sleeveless dresses. They were in sombre mood. Father Peter was dead: he had committed suicide in custody, having become depressed about his crimes, according to the police. Carla wondered if he had been beaten as her father had. It seemed dreadfully likely.

There were dozens more in police cells all over Germany. Some had protested publicly about the killing of the handicapped, others had done no more than pass round copies of Bishop von Galen’s sermon. She wondered if all of them would be tortured. She wondered how long she would escape such a fate.

Werner came out of the house with a tray. He carried it across the lawn to the pagoda. Cheerily he said: ‘How about some lemonade, girls?’

Carla looked away. ‘No, thank you,’ she said coldly. She did not understand how he could pretend to be her friend after the cowardice he had shown.

Frieda said: ‘Not for me.’

‘I hope we’re not bad friends,’ Werner said, looking at Carla.

How could he say such a thing? Of course they were bad friends.

Frieda said: ‘Father Peter is dead, Werner.’

Carla added: ‘Probably tortured to death by the Gestapo, because he refused to accept the murder of people such as your brother. My father is dead, too, for the same reason. Lots of other people are in jail or in camps. But you kept your cushy desk job, so that’s all right.’

Werner looked hurt. That surprised Carla. She had expected defiance, or at least an effort at insouciance. But he seemed genuinely upset. He said: ‘Don’t you think we each have our different ways of doing what we can?’

This was feeble. ‘You did nothing!’ Carla said.

‘Perhaps,’ he said sadly. ‘No lemonade, then?’

Neither girl answered, and he went back to the house.

Carla was indignant and angry, but she could not help also feeling regret. Before she discovered that Werner was a coward she had been embarking on a romance with him. She had liked him a lot, ten times more than any other boy she had kissed. She was not quite heartbroken, but she was deeply disappointed.

Frieda was luckier. This thought was prompted by the sight of Heinrich coming out of the house. Frieda was glamorous and fun-loving, and Heinrich was brooding and intense, but somehow they made a pair. ‘Are you in love with him?’ Carla said while he was still out of earshot.

‘I don’t know yet,’ Frieda replied. ‘He’s terribly sweet, though. I kind of adore him.’

That might not be love, Carla thought, but it was well on the way.

Heinrich was bursting with news. ‘I had to come and tell you right away,’ he said. ‘My father told me after lunch.’

‘What?’ said Frieda.

‘The government has cancelled the project. It was called Aktion T4. The killing of the handicapped. They’re stopping.’