The next hour was one of the most miserable I’d ever known. I spent it shitting bricks that the head-shed might call off the free-fall. They might decide to leave Sasha and me to try and spring the prisoners. I could just hear Bill saying, ‘Make your own way out as best you can.’ Fucking thanks, I thought. I kept reasoning, No, they can’t do that – they’d be four guys down rather than two. But for all my wishful thinking I couldn’t be sure.

As the snow kept floating down in a dense pall, I speculated about where the bomb might be heading. Back to Moscow, I felt certain. What if the Chechens used it to threaten the Russian government, just as the Americans had been planning to do? What an irony that would be.

I convinced myself that the blizzard was going to continue all day and all night, and that Akula’s men had come up to move the bomb while they still could, before everyone got snowed in.

At last the snowflakes began to thin, and the sky lightened as the storm moved on towards the north-east. I waited till I could see a patch of blue sky among the clouds, then tried the Satcom again.

This time, thank God, the call went straight through.

‘Bill,’ I exclaimed. ‘They’ve moved the fucker!’

‘I know. Where the hell have you been?’

‘Nowhere,’ I told him. ‘The comms went down in a snowstorm.’

‘I see. Well, the device has been on the move.’

‘I was trying to tell you that. Some guys came and carried off the components in a truck. Bill – how far’s Grozny from here?’

‘Fifty ks. That’s where it’s gone. The Yanks have tracked it that far.’

‘The damned thing’ll be airborne by now,’ I said. ‘If it’s gone off the air again it means it’s inside a plane. What do we do?’

‘Wait one.’

I held on, hearing nothing but a roar of static. Then Bill came back and said, ‘We’re going ahead with the drop, weather permitting. We’re just waiting for the latest forecast.’

‘The sky’s clearing here,’ I told him. ‘It’s bloody cold, too.’

‘OK, Geordie. I’ll come back to you in a minute.’

I waited tensely, longing for the hit to be over and done with. ‘Let’s just grab our guys,’ I said to myself, ‘and get out of this arsehole of a place.’

Then Bill came through again. The forecast was good: clear skies behind the storm, and a hard frost. The plan remained on. What was more, they’d decided to advance the drop by half an hour, moving it to the original time of 1900. The two Chinooks were on their way to Nalchik, and would sit there waiting to hop over the mountain as soon as they were summoned.