‘Like in Woody Allen’s film, Zelig. Zelig is so insecure that he becomes a human chameleon, taking on not only the style and manner but also the appearance of the people he moves among. It’s the big danger for the undercover cop. You spend so much time with these people, alienated from your own culture, that you start to identify with them.’

‘You go native,’ Carol said.

‘Precisely. E-mail is all very well for the exchange of information, but it will not protect you from yourself. For that, we need face-to-face contact.’

Gandle looked dubious. ‘You already said that Radecki’s people are going to be suspicious around Carol. They’re going to be watching her. And, with respect, Petra, you’re a Berlin cop. Somebody’s bound to recognize you. The last thing we want is to take the risk of regular meetings between the pair of you.’

‘I think we can do this at no risk to Carol,’ Petra said firmly. ‘There is a very upscale women’s health club a few blocks away from the apartment. As well as the gym and the swimming pool, they have private sauna suites that members can book for half-hour sessions. This is not a place where Krasic or anyone else in Radecki’s inner circle can follow us. Trust me, Larry, I would not make an arrangement that would expose Carol.’

Gandle looked dubious, but Carol nodded. ‘I agree. it’s important to keep me connected to the real world. Besides, sometimes you need to talk something through face to face. There might be things that I see or hear but don’t understand the significance of, things I might leave out of a written report because I don’t realize they’re important. But Petra will know the right questions to ask to draw the information out of me. I think she’s right, Larry. We need that regular contact.’

Gandle fiddled with his silk tie. ‘I don’t know, Carol. You will be going in and out of Berlin every seven to ten days, we were thinking that you’d get your debriefs then. In London or here.’

‘Ten days can be a very long time on the front line,’ Petra said. ‘It’s up to Carol, of course …’ She met Carol’s eyes, an expectant look on her face.