Prince nodded, but Hanne shook her head angrily.

‘You’re forgetting a possible British connection – what about Charles Falmer? I know he was murdered on the train and the money wasn’t with him, but surely that all points to something going on here.’

‘That would be a matter for the Security Service or Special Branch.’ Gilbey had returned to his seat alongside theirs. ‘Richard knows all about that – your last case involved Nazi sympathisers in this country.’

‘Yes, sir, and I have to say I believe Hanne is right, actually. There certainly seems to be a very strong case to be made for saying that Falmer was probably a courier, bringing money from London to help fund the Kestrel Line. If that’s true, then surely there’s an obligation to investigate further – after all, we know about this art gallery, don’t we? If we find out what’s going on here, it could open up the Kestrel Line for us.’

‘I suppose I could argue that as we came across this intelligence while on an operation overseas, we can justify continuing the investigation here. After all, we don’t want to be presenting gifts to the Security Service after we’ve done all the hard work, do we?’

Hanne and Prince both said they agreed.

‘We’d better keep you chaps out of it at this end – Prince, you’re known from your last investigation, and in any case it’s possible that word about you may have got back here from Germany, you never know. You go back to Lincoln; I imagine you’ll be wanting to see your boy, won’t you? If anything crops up and it’s worth reopening the case, I’ll be in touch. You have my word.’

He leaned forward and shook hands with both of them rather formally.

‘And who will investigate matters here, sir?’

‘I have just the man in mind.’

There was a certain confidence in Sir Roland Pearson’s step as he turned from Old Bond Street into Burlington Gardens. For the first time in weeks, the fog of lethargy that had hung over him was lifted.

Sir Roland took the view that his life was unquestionably made up of more achievements than setbacks, though he was aware that one of his failings was to dwell far too much on the latter, and he’d certainly been doing plenty of that recently.

Early in 1940, Winston Churchill had appointed him to his staff at Downing Street, where his role was to coordinate the activities of the various intelligence and security agencies. It was a job that was hard to define and even harder to get right, but he very quickly proved to be indispensable. He was in many ways an invisible man: no one outside Whitehall and the intelligence agencies knew of him, but for those who did, he was all-powerful. He had, as people would say, ‘Winston’s ear’.

But when Winston lost the election, he had nowhere to go other than his apartment overlooking Birdcage Walk, and his club. It was from Boodle’s that Tom Gilbey had rescued him with the offer of the mission he was now embarking on. He had done his homework and it all sounded rather fun.