Mine. Stuart’s eyes flashed with a sort of manic glee when he said the word. There was something wrong inside his head. Something deeper and more dysfunctional than just obsessive greed or cold-blooded acquisitiveness. Ben could see it stamped all over his face.

‘I don’t get it, Stuart. You’ve got everything in the world, and yet you’d risk it all for a bunch of shiny coins.’

Stuart chuckled. ‘Well, now, the word “bunch” would be something of an understatement, as you and I are both very well aware. To my certain knowledge, until your associate Ross Campbell got very lucky indeed, no more than a single bag of French Louis d’or had ever been recovered out of the one million, two hundred thousand livres of foreign aid that were secretly shipped to Scotland in September 1746 by French warships carrying munitions and funds to support the Jacobite uprising against the British crown.’

‘So you’re a historian now,’ Ben said.

‘Oh, I’m a little more than that. The man who led that uprising was my direct ancestor. That makes it highly personal to me.’

‘Bonnie Prince Charlie.’

‘None other. The seven large caskets containing the payroll for his rebel army were moved some twenty miles inland and buried in the ancient pine forest somewhere near the loch. Which means that the vast bulk of the gold has remained hidden there ever since, until now. In modern currency, something in the region of ten million pounds’ worth. But of course, I needn’t tell you that, since it seems you already have it in your possession.’

Ben said nothing. He was acutely aware that his subterfuge was running out of road here. All he could do was keep the lie going for as long as he could ride it, and hope that either he found a new way to use it, or something better came to him – fast.