Ben was surprised, because he knew all about the Pathfinder Platoon. Primarily a recon unit, they often worked in an Advance Force operations role as support to SAS. Their troopers were some of the toughest and most disciplined in the business, who received a level of training second only to the most elite regiments of the joint Special Forces family.

‘Of all of them, you would say that Hacker was the biggest waste of a good soldier,’ Monty said. ‘By all accounts he was a master with a rifle, too. Won first-place medal in the AOSC long-range sniper event, two years in a row.’

AOSC stood for Army Operational Shooting Competition, the British Forces’ premier marksmanship tournament, held annually at Bisley in Surrey. To even qualify, you had to be excellent. To come away a winner was a superlative achievement. Ben had only won it once.

‘And then it all went badly awry,’ Monty went on, shaking his head. ‘As you’ll see from his file, Hacker earned his DD eight years ago following his alleged involvement in a gun-running racket supplying weapons, ammunition and explosives that had been magicked out of British military arsenals to members of organised crime gangs in the UK, Sweden and Germany.’

‘Tell me more about him,’ Ben said.

Monty replied, ‘Turn to the last page of his dossier and you’ll see that he’s now employed as international head of security for an independent investments company called Stuart Corporate Enterprises Ltd, based in Scotland but with offices worldwide. I did some digging into the firm in case it was some kind of front for illicit activities. You never know. But it all seems perfectly above board, and quite a large-scale set-up. Which makes Hacker one of the fortunate few with his background who still somehow manage to land cushy legitimate jobs despite their dubious past history. But then, he was always one of the clever ones.’

Ben and Grace exchanged glances. Ben asked Monty, ‘Based where in Scotland?’

The question caught the colonel off-balance. He puzzled for a moment, scratching his head. ‘Lord, I forget exactly. I’d have to check. As I recall, it was somewhere in the Highlands. An unlikely location, I remember thinking at the time. Fort something. The company owner is some multimillionaire or other who owns a castle up there. It’s coming back to me now. Charles Stuart, that was his name. Like Bonnie Prince Charlie, the Young Pretender.’

‘There are three Highland forts,’ Grace said. ‘Spaced out in a diagonal line spanning northern Scotland from the Firth of Lorne to the Moray Firth. Fort George in the east, Fort Augustus in the middle and Fort William in the west. So which is it?’

‘Fort William,’ Monty remembered suddenly. ‘I’m sure it was that one. Yes, yes, of course. That’s where the Commando monument is, at Spean Bridge. Where Churchill sent our boys to train with the American Army Rangers during the war.’