But there was worse to come.

The tall soldier pointed at Rebecca.

She cringed away from him and tried to hide behind Carla.

A second man, small with fair hair, grabbed Rebecca and pulled her away. Rebecca screamed, and the small man grinned as if he liked the sound.

Carla had a dreadful feeling she knew what was going to happen next.

The short man held Rebecca firmly while the tall man squeezed her breasts roughly, then said something that made them both laugh.

There were cries of protest from the people all around.

The tall man levelled his gun. Carla was terrified he would fire. He would kill and wound dozens of people if he pulled the trigger of a submachine gun in a crowded room.

Everyone else realized the danger, and they went quiet.

The two soldiers backed towards the door, taking Rebecca with them. She yelled and struggled, but she could not break the small soldier’s grip.

When they reached the door, Carla stepped forward and cried: ‘Wait!’

Something in her voice made them stop.

‘She’s too young,’ Carla said. ‘Only thirteen!’ She did not know whether they understood her. She held up two hands, showing ten fingers, then one hand showing three. ‘Thirteen!’

The tall soldier seemed to understand her. He grinned and said in German: ‘Frau ist frau.’ A woman is a woman.

Carla found herself saying: ‘You need a real woman.’ She walked slowly forward. ‘Take me, instead.’ She tried to smile seductively. ‘I’m not a child. I know what to do.’ She came close, close enough to smell the rank odour of a man who had not bathed for months. Trying to conceal her distaste, she lowered her voice and said: ‘I understand what a man wants.’ She touched her own breast suggestively. ‘Forget the child.’

The tall soldier looked again at Rebecca. Her eyes were red with weeping and her nose was running, which helpfully made her look more like a child, less like a woman.

He looked back at Carla.

She said: ‘There’s a bed upstairs. Shall I show you where?’

Again she was not sure he understood the words, but she took him by the hand and he followed her up the steps to the ground floor.

The fair one let go of Rebecca and came after.

Now that she had succeeded, Carla regretted her bravado. She wanted to break away from the Russians and run. But they would probably shoot her down then go back to Rebecca. Carla thought of the devastated child who had lost both parents yesterday. To be raped the next day would surely destroy her spirit for ever. Carla had to save her.

I will not be smashed by this, Carla thought. I can live through it. I will be myself again afterwards.

She led them to the electrocardiogram room. She felt cold, as if her heart were freezing and her thoughts becoming sluggish. Next to the bed was a can of the grease used by the doctors to improve the conductivity of the terminals. She pulled off her underpants, then took a large dob of grease and pushed it into her vagina. That might save her from bleeding.