I smile into Tomas’s pale, drawn face. He is finally going to join the Hitler Youth, and his father will be protected from the evil of communism. Perhaps the Gestapo might even find him a job.

It has all gone so much better than I ever imagined it would.

19 August 1934

‘Look!’ Erna points up to the top of the monkey enclosure. ‘We’re in luck!’

We prop our bikes next to a bench behind the zoo, where it backs onto Rosental park. A small group of the flat-faced grey creatures sit close to the side of the cage, high up on wooden poles. One of them swings down onto a platform where pieces of fruit are scattered. It grabs a slice of apple and, clasping it tightly in its little fist, the animal climbs back onto the pole. There it sits, nibbling while its friends squawk and chatter with each other like a bunch of old ladies.

In front of us, small children play on the flat grassy expanse of Rosental in the warm August sunshine and dogs bound in great, loopy circles. From my bag I take out the two slices of linzertorte, wrapped in brown paper, and offer one to Erna. We sit and eat in silence.

A monkey-couple crouch apart from the rest, close together, preening and checking each other’s fur. The quiet, gentle movements are broken from time to time as one or other finds something, a flea or a louse perhaps, and swiftly grabbing it, pops it into its mouth.

‘Imagine if people did that.’ Erna suddenly giggles at the monkey-couple and nudges me with her elbow. ‘Imagine you doing that with your sweetheart when you get one.’

I almost spit out my mouthful of sweet pastry and jam.

‘Erna!’ I splutter. ‘Shhh…’

She turns and looks at me, wickedness flickering in her eyes. ‘Perhaps you already have someone in mind.’

‘Don’t be ridiculous. We’re only twelve.’

‘I’m nearly thirteen. Anyway, what about Karl?’ She looks at me sideways.

‘What about him?’

‘He’s awfully handsome.’

‘Karl?’ I laugh. ‘He hardly ever washes and almost never changes his pants and vest.’ Something quivers in my belly. A snake flickering its tongue. I carefully lick the jam off my fingers. ‘Re-enacting famous battles. Aeroplanes. Football,’ I count them off. ‘That’s what Karl likes.’

I study Erna’s profile while she chews and watches the monkeys. The delicate sweep of her nose, her high cheek bones and smooth, milky skin. She really is impossibly pretty…

But Karl’s not interested in girls.

She lets out a long sigh and scrunches her paper bag into a small ball.

‘I told my father about you,’ she says, turning the ball round and round in her hands. ‘He said not to be friends.’

‘Why not?’ I stare at her in surprise.

‘It’s not you he doesn’t like,’ she says hurriedly, ‘it’s your father.’

‘But he doesn’t even know my father!’

‘I probably shouldn’t say,’ she says, squeezing the ball to make it flat. ‘It’s only because he’s wrong. I should be friends with you, and whatever he says won’t change a thing. You’ll always be my best friend, won’t you, Hetty?’