‘A small, damaged but still decipherable piece of stone tablet that showed, or at least suggested, that Alexander had established a fort up here on the site of the original Zakara.’

‘But no actual evidence of a new city being founded.’

‘No, that evidence had to wait a few months to be discovered, until Dad was able to mount an expedition here with a crew of local guides and diggers.’

‘What did he find?’ Wolf asked, with a predatory twinkle in his eyes.

‘In a hollow in the rocks, buried a couple of feet below the ground, a small hoard of Alexandrine coins and other gold artefacts from the period. It wasn’t all he might have hoped for, but it was enough incentive to keep digging. If only it had worked out that way.’

‘Why didn’t he?’

Madison replied, ‘Because a freak blizzard suddenly hit them just as they were preparing to set up a base camp. It lasted a whole day and a night, pinning them in a tent and half-burying them in a foot of snow. One of his Afghan guides suffered serious frostbite, and another almost died of hypothermia. Dad had to abort the dig to rush them away to a hospital.’

‘Is there one?’ Wolf asked.

‘Not for a few hundred miles. By the time they got there it was touch and go whether the hypothermic guy would pull through, but thankfully he did. Dad flew home to the States and a month went by before he could return. He spent that time setting up plans and getting all the contacts in place for a major new excavation that he’d have funded out of his own pocket. If he was right, it was set to become the find of the century. Then, just as he was finally ready to come back and continue the dig … well, you might be able to guess what happened next. This was late December, 1979.’

‘The Soviet invasion,’ Ben said.

‘When the Russian tanks rolled into Kabul, all his plans were totally blown to pieces. Suddenly, after years of relative stability, Afghanistan was an active war zone again, the hills full of Soviet troops shooting it out with the guerrillas, and it was impossible for him to even enter the country, let alone mount an archaeological dig.’

‘I’d have been climbing the walls,’ Wolf said.