‘Really?’ says Younghusband, taking the bait, setting down his mess tin of stew and wiping both sides of his hands on his shirt. ‘Are you a gambling man, Mr Notovitch? What would you wager for a race against me?’

‘I’d do it for the honour of my country,’ says Nicolas, ‘but I’m not sure what you would have to stake against it.’

‘If you’re so confident of winning that you feel able to insult my nation, why not wager Skobelev’s canteen?’ says Younghusband, his voice grown strained and harsh.

‘What do you have that could possibly equal its value?’

‘I have charts of every valley between here and Peking. Some one-to-fifty-thousand scale. Ordnance-quality. Perfect for someone who was planning military manoeuvres in the area. I expect they’d be appreciated by your paymasters in Moscow.’

‘My paymasters are in Saint Petersburg. Moscow hasn’t been the capital of Russia for a hundred and fifty years, you insular macaroni. Let me see those charts.’

Younghusband throws him a handful of rolled maps from his saddlebags. They are just as he promised: the finest works of British Imperial cartographers. This is intelligence worth having.

‘Walid,’ says Notovitch, addressing one of his men. ‘Saddle Tengri for me.’

The course they choose runs the length of the valley floor, includes a turn at the far end and finishes back at the starting line. There is a delay of twenty minutes while the guides remove hazardous rocks from the course. Younghusband performs callisthenic stretches as they wait.

It is agreed that Walid will signal the start with a pistol-shot.

Tengri has been Nicolas’s mount since he bought her in Bishkek. She is grey, with the unflappable temperament of a Buddha, and faster than sunlight. Nicolas is confident of winning this, but, by the look of things, so is Younghusband.

At the pistol-shot, time seems suspended for a second. The sound repeats around the valley. Younghusband is already off, standing up in his shortened stirrups like a jockey.