She won’t risk arguing with that. We stare at each other for a moment. She gives a quick nod and purses her lips. Moves on to the next girl.

I push my way through the chattering crowd at the doorway, spilling into the corridor, searching for a red-gold sweep of hair. I’m carried along with the tide of girls to the gymnastics hall where they splinter into groups, sheltering from the rain outside.

She’s waiting for me. We ignore the rain and run down the steps into the deserted playground. Huddling against the building to stave off the worst of the drizzle, I find I can’t meet her eyes.

‘About yesterday… What I said about Karl…’ She pauses. ‘I’m sorry if it came as a shock.’

‘It did, rather.’

‘And what you told me, about Walter. That was rather a shock too. I barely slept last night.’

‘Me neither.’

‘Hett—’

‘Thing is, Erna,’ I summon the courage to look into her flecked green eyes, ‘once you find out someone isn’t what you think they are, it’s hard to trust. Hard to go on, as we were.’

‘Exactly!’ Erna’s face becomes animated. ‘Hetty, I trust you to the end of the earth. You could have informed on my father. You heard what he said, but you didn’t. Now I know how you feel about Walter and the treatment of people who aren’t racially pure. Well, that just brings us closer together. Perhaps you can help the fight against—’

‘Oh, Erna. I want to help. I wish I could. But – but I’m not sure what I can do. Vati is travelling up the party ranks and Mutti supports everything he does. At least, she did. She’s so broken now, after Karl, that I’m not sure she’ll ever recover. Besides, Walter says I should keep my head down. Stay safe, because with luck, all this will one day be over and then we can be together. Oh, I don’t know. What on earth can we two girls, with no money or influence, actually do?’

‘But don’t you see what you’ve done already? It’s incredible. You’ve dared to think differently.’

‘It’s not incredible, Erna. I’ve only fallen in love, that’s all. If it hadn’t been for Walter, I’d be…’ What would I be? I’d still be as fervent a follower as I was. I’d never dare to think differently. I’d still believe I was destined for greatness as Hitler’s child. Wouldn’t I? There’s a pounding in my temples. ‘I don’t know what I’d be,’ I say quietly.

‘It doesn’t matter what you would or wouldn’t be. What matters is now. You can help us. The resistance. As things get worse, more and more will join. You’ll see.’ Erna lays a hand on my arm. ‘Your father must have information. Surely you must hear things, see things?’

‘You’re asking me to spy on my father?’

She looks at me hard. ‘Do you want to help Walter and his family and thousands like him? Without trial, ever increasing numbers of Jews and political opponents are being herded into camps. The Nazis are building more and more – they want to force Jewish people, all of them, out of their homes, into ghettoes. And that’s not all. The Nazis’ promise of peace and prosperity – it’s lies. They are pushing us towards war. Hitler wants his empire and if we don’t do something, where will it end? It’s our future, Hett. We’re the young. We should be fighting it.’