He and his team of Afghan diggers had climbed several hundred metres from the valley far below. The small convoy of vehicles that had brought them as far as they could up the mountainside looked like miniature models from up here. Abdul and the others halted for a moment while their boss stood panting and gasping a few moments longer. One or two of them exchanged private grins at the expense of the wealthy American guy who was paying them for this little expedition. Paying a lot of money, because this was by no means a safe place to be. The men were all carrying rifles as well as shovels and picks.

‘Give me a minute, guys,’ Rigby said. As he clapped his hands to get the circulation going again he gazed at the landscape around him, the same bleakly majestic scenery that had remained completely unchanged since Alexander the Great had marched his vast army though these same mountains, more than three hundred years before the birth of Christ. Even back in Alexander’s day this land had already been steeped in ancient history and soaked in the blood of countless dead. So many wars had been fought, so many had cruelly perished here. But Rigby understood the truth: that it was this barren, hostile, pitiless place itself that had been the ruination of every successive invading force, no matter how powerful, that had tried to make their conquest against it.

That was an intimidating thought for an outsider like Rigby Cahill, however well intentioned, who had made it his business to travel from a faraway land to disturb Afghanistan’s ancient secrets and wake up its ghosts. Hunting for lost antiquities was what he did for a living, whether it was relocating caches of stolen art from Nazi treasure trains, diving on sunken galleons off the coast of Sumatra or hacking through the South American jungle in search of Paititi, the fabled Incan City of Gold. He was no stranger to the sometimes hostile and dangerous corners of the world. And yet, this place haunted him. The looming white-capped mountains seemed to be watching, as though they knew something. The eerie moaning whistle of the wind made Rigby shiver with something more than cold.

He moved on, but only a few steps before he halted again, thinking he could make out a different sound half masked behind that of the wind. A distant crackling rumble. Like an earthquake, perhaps. Or a faraway clap of thunder? Craning his neck upwards he scanned the wintry pallor of the sky, a vast great dome above them, the cold sun directly overhead reflecting dazzlingly against the snowy peaks. He couldn’t see a single cloud. He glanced quizzically at Abdul, who shook his head with a knowing look and said, ‘Gunfire. The Mujahideen are not far away. We must be careful.’