Ernst is on him in an instant, the other boys yelling encouragement. He’s twice the size of Tomas and anger boils; red-hot fury at the bullies who always pick on scrawny Tomas. In my mind, the months fall away and I’m back on the street behind our old block of flats with Tomas, when it was us two against the dirty swine who beat him to a pulp just for the fun of it.

I launch myself at Ernst’s neck, digging my fingernails into the soft flesh beneath his chin. The three of us drop to the ground, Ernst beneath me but reaching back to grab some part of me. He lets out an almighty yell and tries to push me off, but I’m clawing wildly at his face.

‘STOP THIS AT ONCE!’ A woman’s voice, fierce and loud. Hands grip my shoulders and pull me away from Ernst. I’m spun around and the hands let go.

‘Fräulein Herta! Fighting with boys like a dog! You should be ashamed of yourself.’ Bertha, her cheeks blotchy purple, eyes looking like they might pop out of her head, stands in front of me. ‘What on earth would your mother think?’ Her chest rises and falls as her breath puffs out like steam from the big, black kettle on the range.

Ernst and Tomas disentangle themselves and slowly get up, covered in snow. The other three Brandt brothers stand still, gawping at Bertha.

She shifts her gaze to Ernst and gasps. His face is a mess and my nails have dirt and bits of his bloodied skin beneath them. Tomas scrabbles in the snow, finds his glasses, broken now, and shoves them, lopsidedly, back on.

‘Look what you’ve done to that boy’s face, Fräulein Herta!’ Bertha exclaims. ‘You’ve drawn blood!’

‘But it was Ernst who started it, Bertha. He attacked Tomas and I was trying to save him. That lot,’ I point at the other brothers, ‘they would’ve joined in, if I hadn’t… The odds were unfair.’

Bertha looks at Tomas. ‘Is this true?’ she asks crisply.

Tomas nods and stares at the ground.

Ernst dabs his bloodied cheek with his handkerchief and says nothing.

‘Hmm,’ she grunts. ‘You should know better than to fight with a girl,’ she says, looking at each of the brothers in turn. ‘You’d better get off home before I cuff the lot of you.’

Ernst thrusts his shoulders back and juts his chin out as he saunters off, his brothers trailing behind him.

‘You’re pathetic,’ he hisses to Tomas as he passes. ‘Need a girl to fight your battles for you.’ He spits on the snow.

Bertha watches him go, her arms crossed over her chest. She looks at me, her face softening. ‘That was brave, Fräulein,’ she says, ‘to stand up for a friend. But silly all the same. You’re a young lady, and young ladies do not fight. That’s all there is to it. Now, off home with you.’

Tomas and I walk slowly back to my big house on Fritzschestrasse, from where he will carry on to the tiny flat above his uncle’s shop on Hallische Strasse. Unlikely friends, thrown together long ago, through lack of alternative.