Warmth at the sight of Erna giggling at my joke spreads like hot chocolate. Everything is suddenly possible and within my grasp. I only have to reach out and take it.

The lesson ends all too soon and we must go inside.

This time, I squeeze onto Erna’s bench. We have a new lesson each day, slotted between other classes. The Life of the Führer. We are to learn about the great man, Adolf Hitler, Frau Schmidt explains, by studying his struggles, his courage and fortitude. Frau Schmidt is misty-eyed as she speaks of his suffering, and of his wisdom. We shall, she tells us, once we know everything, admire and love him, just as much as she does. And then we sing.

Belting out the ‘Horst Wessel Lied’, I glance out of the window. The older classes are on their break. I scan the heads and find Karl. At the centre of the crowd, he throws his head back in laughter. I smile as I watch him, then turn my gaze to a solitary figure sitting far from the others on a bench, legs crossed, one foot swinging lazily back and forth. His blond head is bent over, engrossed in a book. Walter. How funny he is! While Karl and his other friends show off and compete with each other, Walter does the opposite. He shuts himself away with his books. My heart expands as I watch him.

Our singing comes to an end with our daily chant of gratitude:

Führer, my Führer given me by God,

Protect and preserve my life for long.

You rescued Germany from its deepest need.

I thank you for my daily bread.

Stay for a long time with me, leave me not.

Führer, my Führer, my faith, my light

Hail my Führer.

Mutti is out fundraising when Karl and I arrive home from school in a downpour.

‘Once you’re dry, you can have lunch with Ingrid and me,’ Bertha tells us, setting out four places at the big oak table in the flagstone-floored kitchen.

I climb the stairs to change my clothes. It was so different when we lived in the flat. It had been just Karl, Mutti and me since Vati was often working. We were a little unit of three, eating together, Karl and me sleeping together. We’d shop with Mutti and help her prepare meals in the kitchen. She would sing French songs and tell us stories from her childhood in France, before she came to live in Germany. She had more to do back then, because we didn’t have a cook and a maid, yet, oddly, she seemed to have more time for us. Now she rushes here and there doing her charity work and seeing friends, often leaving us in Bertha’s care. I wonder if she sometimes forgets we even exist.

I click on the smart new wireless Vati has given me, which sits on top of my writing desk. They are replaying the speech that Dr Gross, head of the Nazi Party’s Racial Policy Office, made last night to the youth of Germany. Karl and I had sat and listened to the whole thing dutifully before dinner.