The men propped their rifles against boulders, unslung their packs, grabbed their shovels and picks and set to work. Rigby stood back and watched, but his impatience soon got the better of him and he grabbed a pick for himself and joined them. He was physically quite out of shape, as the climb had proved, but now his enthusiasm was unstoppable as he hacked and chipped breathlessly away. Gradually, they hollowed out the top of the mound and spread their efforts over the surrounding area. It was tough work and sweat stung Rigby’s eyes despite the cold. The distant gunfire seemed to have died away, though he was barely even aware of it.

Just when Rigby was beginning to doubt his judgement as to where they should be digging, his pick blade hit something hard that gave a dull clang unlike the sound of a normal rock. He kept working at it, pouring sweat and puffing like an asthmatic rhinoceros, and within a few more minutes he’d uncovered what appeared to be the corner of a stone block. He got down on his knees and carefully brushed away the loose dirt. The block’s straight edges were chipped and crumbled with age but beyond any doubt a manmade object. There was another one right beside it, some bits of the ancient mortar still visible.

He called to the workers and showed them what he’d discovered, and they all started digging energetically to uncover more of it. ‘Careful, careful,’ he kept urging them, even though none except Abdul could understand a word he said. ‘These stone blocks are over two thousand years old!’

The hours dragged wearily by. Shovel load by shovel load, boulder by boulder, they stripped away the rubble of two millennia and the first tantalising outline of the ancient walls revealed itself. The temperature had dropped a couple more degrees as evening approached, and Rigby’s teeth were chattering. The threatening gunfire in the distance was long gone by now, but that didn’t mean that the Mujahideen warriors wouldn’t be back. Many different units belonging to different factions patrolled these hills regularly, on foot, in jeeps or on horseback, bristling with weapons. These were lean, tough, battle-hardened, implacable men who’d known nothing but fighting and hardship all their lives. After years of bitter guerrilla war, with backing from their secret allies the CIA, they’d managed to defeat the might of the USSR. What enemy would they set their sights on next?

The light was beginning to fail by the time Rigby’s men had unearthed the rectangular shape of a large stone slab, broad and long enough to be the floor base of a significant building. There was no longer much doubt in Rigby’s mind of what they were looking at, but he still needed the final proof.

It wouldn’t be long before he had it.