I reached out towards him. He pushed me away. ‘Surely there’s something I can do to try to make it up to you, Arnie?’

He slumped down next to me on the sofa. Now he’s holding his head in his hands. Finally, he looked up and met my eyes. His were cold and steely.

‘This can’t be undone, Lotti. It’s too late. But I want you to arrange another meeting with the man who gave us these.’ He waved the documents around in the air again. ‘At the very least, I want to give him a piece of my mind and try to discover his motives.’

*

Given the damage he’s caused, I half expect my contact not to answer when I call him. But then, perhaps the man who calls himself Fyodor Chernyshevsky is just another Stasi dupe, like I am. Persuading him to meet us near the new pub in Gorbitz is easier than I expect. He doesn’t seem to realise the mess he’s made of another man’s life.

By the time we get to Gorbitz, and are waiting outside Zum grüner Heinrich, Arnie has calmed down a little, although he barely speaks to me on the bus or train ride there. We only have to wait about five minutes until ‘Chernyshevsky’ turns up. More and more I’m thinking he’s probably not Russian at all. After all, we East Germans all learn Russian at school. He’s probably just another Stasi unofficial informer, like I am.

The man hisses at us to follow him, and leads us to an area where some of the apartment blocks haven’t been completed and the street lighting hasn’t yet been switched on. It will be easier to talk there, he says.

I don’t like the semi-darkness, especially given the mood Arnie is in. Anything could happen.

When ‘Chernyshevsky’ finally gets to somewhere he feels comfortable, he turns towards Arnie.

‘What was it you wanted?’ he asks.

Just the fact that the question has been asked suddenly transforms Arnie into a raging madman. He’s yelling at the man, beating his chest with his fists. The man can’t understand what’s going on. He tries to explain he was just asked to do a job for a small amount of money, that he had no idea the documents were faked. Still, Arnie berates him and has now grabbed hold of him. At first, the man backs away onto some duckboards between the newly laid concrete, but then realises he’s stronger. He gets Arnie in a headlock, and starts punching him round the head. I’m worried he’s going to kill him.

‘Let him go,’ I yell.