Vati walks ahead, checking around every corner before we get there, looking all around constantly, signalling for us to follow him. We follow behind him, slightly slower than usual as Otto’s limp is playing up a little. That happens when he is stressed or tired. So we pick our way carefully and stealthily through the streets.

And then we are there. We can see the crowds at Prague’s main station. Tears are flowing down Mutti’s cheeks so fast she doesn’t even try to stop them. She grips my hand on one side and Otto’s on the other.

‘My darlings, my darlings,’ she says over and over. ‘I love you so much.’

Then don’t send us away. The words burn my throat, but I keep them inside.

Vati beckons us towards him. He opens his arms wide and Otto and I fling ourselves into them.

‘We will see you soon,’ he says fiercely as Mutti joins the hug, wrapping the two of us in a cocoon. ‘We will never stop thinking about you, not for one day or one hour or even one second.’

My tears are soaking his coat. I can feel Mutti’s body shaking with sobs.

And then—

‘Mr Bauer, Mr Bauer!’ Someone is calling Vati’s name.

We move apart to see a man running towards us. I recognize him as Mr Janek, one of Vati’s friends. He and Vati fought together when Vati joined up to fight Hitler’s army last year. He’s been to our home. One of the few who still comes. He came only a few weeks ago with his friend Mr Havel. They were sitting on the sofa together when I came into the kitchen. I think they were holding hands. They broke apart quickly when they saw me. I asked Mutti about them afterwards.

‘The Nazis don’t only hate the Jews,’ she said bitterly. ‘They hate anyone who doesn’t conform to their ideas of what a “pure” human being should be like. Even if the reason they hate is for love.’

I didn’t really understand what she meant, but I knew one thing. Mr Janek and Mr Havel were Mutti and Vati’s friends, and those were so few and far between nowadays that I had no doubt whatsoever that they were my friends too.

Mr Janek has reached us now. Up ahead, the crowds at the station seem to be dispersing. What’s happening?

‘The – train – isn’t – going. They won’t let it leave,’ Mr Janek says. He’s panting and his words come out in staccato bursts.

‘Why not?’ Vati asks. ‘Can they get on the next one?’ Even as he speaks, people are passing us to leave the station. Parents in tears, children running behind them.

While Mr Janek catches his breath, Vati grabs the arm of a father passing us with his three children. ‘What’s going on? What’s happening?’