Carla was listening. The place was strangely quiet. She had dealt with physically and mentally handicapped people, adults and children, and they were not often silent. Even through these closed doors she should have been able to hear shouts, laughter, crying, voices raised in protest, and nonsensical ravings. But there was nothing. It was more like a morgue.

Frieda tried a new tack. ‘Perhaps you can tell me where my brother’s grave is. I’d like to visit it.’

‘There are no graves. We have an incinerator.’ She immediately corrected herself. ‘A cremation facility.’

Carla said: ‘I noticed the chimney.’

Frieda said: ‘What happened to my brother’s ashes?’

‘They will be sent to you in due course.’

‘Don’t mix them up with anyone else’s, will you?’

The woman’s neck reddened in a blush, and Carla guessed they did mix up the ashes, figuring that no one would know.

Nurse König reappeared, followed by a burly man in the white uniform of a male nurse. The woman said: ‘Ah, Römer. Please escort these girls off the premises.’

‘Just a minute,’ said Frieda. ‘Are you quite sure you’re doing the right thing? I only wanted to see the place where my brother died.’

‘Quite sure.’

‘Then you won’t mind letting me know your name.’

There was a second’s hesitation. ‘Frau Schmidt. Now please leave us.’

Römer moved towards them in a menacing way.

‘We’re going,’ Frieda said frostily. ‘We have no intention of giving Herr Römer an excuse to molest us.’

The man changed course and opened the door for them.

They went out, climbed on their bikes, and rode down the drive. Frieda said: ‘Do you think she believed our story?’

‘Totally,’ said Carla. ‘She didn’t even ask our names. If she had suspected the truth she would have called the police right away.’

‘But we didn’t learn much. We saw the chimney. But we didn’t find anything we could call proof.’

Carla felt a bit down. Getting evidence was not as easy as it sounded.

They returned to the hostel. They washed and changed and went out in search of something to eat. The only café was the one with the grumpy proprietress. They ate potato pancakes with sausage. Afterwards they went to the town’s bar. They ordered beers and spoke cheerfully to the other customers, but no one wanted to talk to them. This in itself was suspicious. People everywhere were wary of strangers, for anyone might be a Nazi snitch, but even so Carla wondered how many towns there were where two young girls could spend an hour in a bar without anyone even trying to flirt with them.

They returned to the hostel for an early night. Carla could not think what else to do. Tomorrow they would return home empty-handed. It seemed incredible that she should know about these awful killings yet be unable to stop them. She felt so frustrated she wanted to scream.

It occurred to her that Frau Schmidt – if that really was her name – might have further thoughts about her visitors. At the time, she had taken Carla and Frieda for what they claimed to be, but she might develop suspicions later, and call the police just to be safe. If that happened, Carla and Frieda would not be hard to find. There were just five people at the hostel tonight and they were the only girls. She listened in fear for the fatal knock on the door.