‘Why would a senior Nazi do that?’

‘Self-interest: to give himself some kind of protection once the war was over. Barrow realised straight away how important the material was, and the man gave him another four rolls of film and said he had a further two hundred and ten hidden away.’

‘Presumably he was after money?’

‘Yes, and he also asked for immunity from prosecution. Barrow says the material is excellent – he has details of some of the other documents the man photographed: lists of senior Nazi Party members, serious crimes committed, SS officers, names of scientists… The Nazis destroyed so many of these records that to have these copies is remarkable. It’s perfect material for the Counter Intelligence Corps, like we stumbled across a gold mine.’

‘How do you know this chap’s genuine? The films he gave you could be all that he has, assuming they’re not fakes.’

‘Our assessment is that both he and the films are genuine. He’s smart, too. We have to get our hands on those films. And there’s something else: as a way of showing we could trust him, he told us where we could find a Nazi war criminal high up on our watch list, a man called Gustav Wagner, a former Gauleiter wanted for war crimes in Poland and Hungary. He was exactly where he told us he’d be.’

‘So what’s stopping you doing the deal with him, Joe? You give him some money and immunity from prosecution and he gives you the rest of the films? I hardly think you need our permission, though it’s awfully nice of you to ask.’

‘It’s not as straightforward as that, Tom. There’s a further condition he’s set before he hands over the rest of the films, and we need your cooperation.’

Jenkins looked more nervous now, running a hand over his cropped hair and wiping perspiration from his brow.

‘The man has a son who’s wanted by you guys. As a condition of him handing over the rest of the films, he wants you to abandon the hunt for his son.’

‘What’s the man’s name, Joe?’

‘Wolfgang Steiner. His son’s name is Friedrich. We want you to call off the hunt for Friedrich Steiner and forget about the Kestrel Line. Letting a minor Nazi go free is a very small price to pay for us getting access to such invaluable intelligence.’

Which was when Tom Gilbey responded by telling the American it was a good try but was completely out of the question. Sir Roland Pearson let out a weary sigh. Jenkins sat defiantly with his arms crossed.

‘Leaving aside the not inconsequential fact that Friedrich Steiner is a war criminal who murdered British agents, there’s also the issue of the Kestrel Line. Not only do we think we’ll find the traitor Edward Palmer on it, but there’s also a distinct possibility that it could lead us to Martin Bormann!’

‘You’re not going to find Bormann, Gilbey; I don’t know why you guys believe that story.’