The trees were neither living nor dead: a Grimm forest of willows convulsed by vanished winds. Their roots sank so deep that they found moisture which never reached the surface, but the thinning sap had desiccated their leaves, and their bark had loosened and split. Behind them a grey piedmont gravel, pushed down from the Tianshan snows, was smeared across hundreds of square miles of sand. In front, the true desert began.

Our spirits rose, as if the weight of eastern China, which lay far behind us, was suddenly lifted. For a moment, I think, my companions too wanted to be alone. As for me, solitude seemed the natural condition of travel. Alone, I was at once more vulnerable and more sensitized, and even China appeared no longer precisely a strange land. I was just a stranger in it, my identity thinned. And this solitude carried an inner excitement, which has been perfectly distinct to me since childhood.

But now the company of my own people – a television camera team – filled me with misgiving. In a film, the lone traveller’s windfalls – the chance intimacies and impulses – are gone. Solitude can only be recreated. Yet our film aimed to record the Chinese Silk Road through my eyes, and I nursed a fantasy that our journey would somehow bifurcate. I would experience it, and they would shoot it. The two processes could be decently separated, just as the writing of a travel book is separate from the journey it records.