Hanne watched the man carefully. Prince had told her all about him. Franz Rauter was a former Abwehr spy master who’d run a successful spy ring in London. When Prince had found him in Berlin at the end of the war, Rauter had undertaken to cooperate in return for a promise that he not be treated as a prisoner. It was agreed that after he’d helped the British, he’d be allowed to return to Germany. Prince had told her it hadn’t been a difficult promise to keep. Rauter was pleasant man, a professional intelligence officer and certainly not a Nazi; it had even been suggested to Tom Gilbey that he might be able to use him as a British agent once he was back in Germany.

Rauter himself was keen on this: he was clearly an Anglophile, and the promise of a new identity appealed to him. Although he’d worked in Berlin for a number of years, he was originally from Hamburg. Somewhere nice in the British zone of western Germany would suit him fine.

Neither he nor Gilbey had imagined his return to Germany would happen quite so soon. Gilbey had received an urgent phone call from Prince on the Thursday evening.

‘We’ve found Alphonse Schweitzer.’

‘Good.’

‘The Russians don’t think he’ll cooperate.’

‘I’m sure he will in time, Prince.’

‘We don’t have time, sir.’

‘Why ever not?’

‘He’s due to be executed first thing Monday morning.’

That was when Prince explained the plan he, Hanne and Gurevich had come up with. Alphonse Schweitzer would be told about a stay of execution and moved to a cell in another block while his sentence was allegedly reviewed by no less a person than Marshal Zhukov. He would share the cell with a stooge who’d hopefully get the information from him.

‘And Schweitzer’s bought all this?’

‘He doesn’t know about the stooge, sir.’

‘Obviously, Prince, don’t treat me like a fool. I meant about his case being reviewed at the last minute by Zhukov?’

‘Apparently he was so relieved he’ll believe anything.’ It was then that Prince had suggested they use Franz Rauter as the stooge. He expected Gilbey to find a good reason why not and was ready to make the case: they needed a German, someone who understood the Gestapo, who was credible and who they could trust. But Gilbey was surprisingly amenable to the idea. So much so that he said he’d bring him over himself.

‘As soon as possible, please, sir.’

They spent the weekend and all day Monday in the safe house in Wilmersdorf briefing Rauter: Schweitzer is the only person we’re aware of who knows the true identity of the Ferret, and we’d like you to get him to tell you.

They came up with a plausible cover story, and by the Monday afternoon Rauter was ready.

Reinhard Möller was about to become an inmate of Hohenschönhausen.

Alphonse Schweitzer was so relieved at his stay of execution that he was more than happy to chat with the man he shared his cell with, especially someone as like-minded and sympathetic as Reinhard Möller – that was, as the man insisted on pointing out, Möller with an ‘ö’ rather than Müller with a ‘ü’.