Minutes later they were joined by that officer. Kapitan Leonid Fyodorov looked improbably young – perhaps in his mid-twenties – with a mop of unruly hair, and black eyes that watched them suspiciously. He also spoke good German.

‘I have assured Kapitan Fyodorov that he has done nothing wrong,’ Gurevich began. ‘This is not a disciplinary matter in any way. I understand that he made these notes at a time when he was interrogating maybe a dozen Nazis a day. His oversight in failing to add his initials and not making the notes more explicit is therefore quite understandable.’

Kapitan Fyodorov nodded, and allowed a thin smile to cross his young face.

‘Perhaps, Fyodorov, it would be best if you explained everything in your own words. Would anyone like some more vodka first?’

Hanne and Prince both said they were fine, thank you very much, and Fyodorov didn’t respond as he opened the file and his notebook. Before he spoke, he stood up and shook hands with the two visitors, looking them both in the eye. He seemed intrigued by them. Prince wondered how Gurevich had explained their presence.

‘Since July, I’ve been working at Hohenschönhausen prison in Lichtenberg.’ He nodded to the window, presumably in the direction of Lichtenberg. ‘My job was – and still is – to interrogate Germans whom we suspect of being involved in war crimes or who held senior positions in the regime. On the twelfth of July, I was told to interrogate a prisoner who’d actually requested to speak with us, which was most unusual. His name was Paul Hoffman, and he was a Kriminaldirektor with the Kripo – the Kriminalpolizei, essentially the detectives in the regular police force, though they came under the Nazi security structure. Hoffman was reasonably senior – a Kriminaldirektor is probably equivalent to your rank of major, which is why he was held in custody.

‘You understand that by then I had interrogated hundreds of men and all claimed they’d never been Nazis, and I can honestly say that Hoffman was the first one I believed and who I actually found likeable. He told me he’d been based at the police station in Wedding and ran the department investigating serious crimes. He said he had nothing to do with anything political or to do with Jews, and I believed him, because such matters weren’t handled at that police station.

‘He also told me that not only was he not a Nazi, but he was actually a communist.’ Fyodorov paused and looked at Hanne and Prince to see if they reacted. ‘I know this sounds remarkable, but according to Hoffman, he’d been a member of the KPD.’

‘The KPD?’

‘Kommunistische Partei Deutschlands – the German Communist Party. He said he’d been a member in the 1920s, and although he’d joined the police in 1929, he’d retained his party card until the organisation went underground in 1933. That was not unusual: many of our comrades did likewise. Many also joined the Nazi Party and—’