Mutti is beside me. She hadn’t even noticed my conversation or Mr Grunberg. She is looking over at the men’s line. ‘Where have they taken them?’ she asks me in a voice I’ve never heard before. Keening.

‘My husband, my son,’ Mutti says. Her legs give way and she begins to sink to the ground.

I gently lift her up again. The guards mustn’t see her like this. I keep an arm around her waist as we edge forward. ‘Mutti, we have to be strong,’ I say, some deep instinct taking over and telling me that I must be in charge now.

‘I know,’ Mutti mumbles, leaning her weight against me. She feels so small. So thin. Fragile. ‘I just don’t know if I have any strength left in me.’

I can’t reply. My throat is clenched taut. Instead, I keep my arm around her waist as we stumble wordlessly along the dusty path.

And then we are near the front of the line. Only a few ahead of us. I don’t know what makes me do it, but I quickly turn to Mutti: my darling, beloved mother, my rock, my heart, my world. I take her face in my hands. ‘I love you, Mutti,’ I say fiercely.

She looks at me. Her chapped lips form the nearest thing to a smile that they are capable of making. ‘I love you too,’ she says, her voice like gravel. ‘I always—’

‘No touching!’ The guard screams in my ear so loudly it makes me jump. I reach up to wipe his spittle off the side of my face. He sees me do it and his face breaks out into a cruel smile. Then he makes a horrible sound in his throat, looks directly into my eyes and spits again.

I feel it run down my cheek, towards my mouth. His grin is daring me to reach up and wipe it off. I know he will do worse if I do, so I leave it.

Another guard pushes me forward. Mutti is in front of me. Facing her is a tall man in SS uniform. He looks at her for two seconds and then points to the left. ‘That way.’

Mutti glances back at me. I start to smile at her. I want to tell her I love her again. I want to remind her to be strong. I want everything for her in that moment. I want those seconds of her looking at me to last for ever.

A guard drags her away and another pushes me forward.

I am standing in front of the tall SS man. His jet-black hair is parted to perfection on one side, his eyes, almost as black, bore into me.

‘Age?’ he says, appraising me.