Matthias almost found himself almost hating the girl. Whatever else he thought of Hitler, he knew that Jesus Christ alone was his Lord and Saviour. In other circumstances, he would have stormed into the principal’s office to demand the song be banned. But he couldn’t do that; he could never draw attention to himself in any way, for that route would lead to disaster.

Another thing he had had to do was to give up the Roman Catholicism of his birth and baptism in favour of worshipping in the local Lutheran church. There were no Catholics in this village, so it was safer that way. The only thing they held on to was the crucifix above their bed.

Nor could he give up teaching. With so many young men disappearing from the profession to join the Wehrmacht or the SS, the principal had made it quite clear that retirement was out of the question until the war in the east had ended. And he had the backing of the local SA leader in this. Again, Matthias Rieger had to accept his lot, and it had kept them safe.

Now, tonight, there was the barking of the dog.

Bismarck was a good dog, a rottweiler. A true and faithful guard dog with a loud and aggressive bark that reverberated around the house if any vehicle or person came within a hundred metres of the property. Rieger woke instantly. It wasn’t just the dog, there was the sound of a vehicle engine and the crunch of wheels on the track. He was out of bed within seconds. He tried to alert Maria, but she was ill and could not easily be woken. There was simply no time to shake her awake and warn her.

So he went straight through to Klara’s room and pulled her from the bed.

‘Pappi?’

‘Come on, Klara, it’s time. You know what to do.’

‘But, Pappi, it’s dark. I’m tired.’

He carried her downstairs in his arms. There wasn’t even time for her to get dressed and so she was still in her pretty new nightgown. In the corridor leading to the back door, he grabbed her coat and buckled shoes – the shoes she had put out for St Nicholas the previous day. Now he helped her push her feet into them and wrapped the coat over her shoulders. Then he urged her out of the door and told her to go, as fast as she could.

‘Run, Klara. Go to the place.’

‘Come with me, Pappi.’ Her eyes were wide and afraid. ‘I don’t want to go alone . . .’

‘I can’t – I’m too slow. Go, Klara. You must go.’

He pushed her across the little lawn into the night. And all the time, Bismarck barked from his post in the hallway at the front of the house.

Klara disappeared into the darkness of the woods just as he heard the sound of the front door being forced open. A shot rang out and the barking ceased.