‘You don’t need me. Europe is swarming with military intelligence officers. You’re spoilt for choice.’

‘That’s not quite accurate,’ Dulles said. ‘We need all the intelligence officers we can get. The de-Nazification process is immense and will take years. There are still hundreds of thousands of Nazis or former Nazis to be questioned and assessed – and we’re very short of German speakers. Honestly, there’s not a man or woman to spare. I’m told you speak pretty good German these days, and this isn’t the sort of mission where you can wander around with a local interpreter in tow.’

‘And you have a score to settle, don’t you?’ Eaton said. It was his first contribution. ‘As far back as 1936, friends of yours died, even your students, thanks to Hitler and his grisly band of criminals. To me, that’s a compelling argument. Oh, and by the way, you wouldn’t be alone in this operation.’

‘Are you coming with me then, Eaton?’

‘I honestly wish I could, but I’m not walking well. And the lack of a left arm doesn’t help. No, you will be accompanied by a young lieutenant named Mozes Heck. You will both be co-opted to the US Counter Intelligence Corps in Garmisch. Heck is a Dutch Jew, who escaped to England in a small sailing dinghy in 1940 and joined the British Army. He knows Bavaria well, having lived there during much of his early life when his father worked in Munich as a physician. The family moved back to Amsterdam, but that didn’t save them. They were all deported east in 1943 and, as far as we know, none of them survived. Mo Heck wants to find Hitler very badly. His strengths are his courage, his motivation, his fluent German and his knowledge of Bavaria and the Tyrol. He is good with a gun and has a visceral loathing of Nazis. You will make a formidable team.’

‘Where is he now?’

‘Back in Bavaria,’ the colonel said. ‘Desperately trawling his way through the displaced persons camps looking for any clue as to the fate of his family. Also hunting for Nazis posing as refugees. He’s very effective but a bit headstrong – which is one of the main reasons we need a man like you.’

‘A man like me? I’m not sure what that means.’

‘Mature,’ Dulles said. ‘Grounded. Steeped in tradecraft. Sensitive to the political reality of a country occupied by four powers who might not always see eye to eye. Analytical and inquiring. Heck is a good, courageous man, but he needs guidance. You’ll be taking the lead, Professor Wilde. You’ll keep him in line.’

‘You want me to be Don Quixote in this mad quest – which would make Mr Heck my Sancho Panza.’

‘But you won’t be tilting at windmills,’ Dulles insisted. ‘It is almost certainly pertinent that Collingham and Harper had mountain gear in the trunk of the car: hiking boots, ropes, crampons, that sort of thing. We have reason to believe that Hitler is in the Alps. This is real and it’s dangerous. Hitler must have people protecting him and they haven’t lost their taste for bloodshed. Once you start asking questions, they will know, and they will do all in their power to stop you.’