Aha! The usual story. I feel emboldened now. What do I have to lose? The cancer is almost certainly a death sentence anyway. ‘So you don’t really want to help me, you just want to shut me up and make sure I don’t rock the boat. At the same time as taking away my job so I have no way of earning an income.’

The friendlier one – the major – sighs. ‘Please don’t prejudge us, Frau Rolf. We do want to help you, and can indeed help you. We want to be able to get you the best medical treatment, give you the best chance to survive. And although – yes – you will have to leave your existing employment, we can make sure you don’t lose out financially. Nothing is off the table, and everything is possible – as long as you co-operate with us.’

‘Co-operate?’ Now I see their game. But if they want something from me, it will have to be worth my while.

‘Yes,’ says the colonel. He’s not that old himself. A lot younger than I am. But, for his years – not a single grey hair on his head – he seems to have climbed the greasy pole remarkably rapidly. ‘For a start, the petitions must stop. And we need your help in another matter, something where you can do great service for the Republic.’

Now I’m getting really suspicious. ‘Oh yes?’

‘Yes,’ says the major. ‘It concerns the English friend of yours.’

Immediately my defences go up. I’m not going to betray Arnie, if that’s what they want. ‘What about him?’ I ask, warily.

Again, it’s the slightly younger one, the major, who answers. If they’re playing good cop, bad cop, he’s certainly been given the ‘good’ role. ‘His research is of great interest to the Republic. To be honest, it’s important to the whole world. And we know it’s very close to your heart.’

I know what he’s driving at. For the first time, I feel terribly self-conscious about the bad side of my face. Their eyes seem to be trained on it, like hungry wolves eyeing their prey. I feel myself reddening, and try to rearrange my hair to hide the burn scars as much as possible. ‘I don’t really know that much about his work,’ I lie. ‘He never really talks about it.’

Now the colonel intervenes. ‘Nevertheless, we know you are close to him. Very close.’ He pulls something from his briefcase. Photographs. Strange shadowy photographs that almost look like negatives. I realise what they are – infra-red, low light images. Captured by some sort of bugging device inside Arnie’s apartment on Leningrader Straße. Showing me – at least my back – hunched over his prone body. You don’t see anything too revealing, but it’s obvious what’s going on. I feel the nausea rising in my throat, and start to get up from the stool.