‘A word, sir? Only if you have a moment, of course – I can always come back later.’ The Scotsman who’d told Prince to call him Douglas was hovering uncertainly, even nervously, in the doorway of the man he’d addressed as ‘sir’. Normally such an approach would have come through his own superior and worked its way up the organisation, but he’d taken advantage of the open door.

The man he’d spoken to slowly peered up from behind his desk and removed his spectacles. He was frowning; almost certainly unsure of the name of the man in the doorway.

‘Hendrie, sir, I worked with you on the Belgian case.’

‘Ah yes, of course. Come in, Hendrie, and do close the door behind you. We don’t want the whole world wandering in, eh?’ Tom Gilbey had a reputation for being blunt, even rude, but he was also one of the few senior people in the organisation willing to make a clear decision rather than setting up a committee to answer any questions asked of him. He was rumoured to be distantly related to the gin family. He’d been known to joke, somewhat bitterly, that they were the tonic branch of the family.

‘You’re aware of the German spy we caught last month in Lincolnshire?’

‘Wolfgang Scholz, awaiting the hangman’s noose at Pentonville. I hear you had some trouble catching him.’

Hendrie nodded. ‘Indeed, sir, devil of a job: we feared we’d lost him somewhere between Lincolnshire and London, and you’ll appreciate what the repercussions would have been, a German spy on the loose.’

‘I would have been one of those repercussions, Hendrie.’ Gilbey had closed the folder in front of him and adopted a pose indicating that he’d become interested in what the other man had to say.

‘We had precious little in the way of clues, sir. I went up to Lincolnshire and had to reveal our hand to the local constabulary, which we try to avoid, as you know. I shouldn’t have worried: the Chief Constable gave me the services of a detective superintendent, a young chap called Prince who turned out to be quite marvellous. We’d drawn a blank, but he was convinced the German hadn’t got very far and he felt someone must be hiding him. He had a hunch it would be someone with far-right sympathies but a low profile. He had the bright idea of looking for people in the area who’d previously been members of the British Union of Fascists, and found a woman who fitted the bill perfectly. He managed to get confessions out of both of them before we could even get our hands on them: a breach of protocol, but shows he has initiative.’

‘That’s an uplifting story, Hendrie, but I’m not sure why you’ve come to tell me about this chap.’