On buses, donkey carts, trains, jeeps and camels, Colin Thubron traces the drifts of the first great trade route out of the heart of China into the mountains of Central Asia, across northern Afghanistan and the plains of Iran into Kurdish Turkey. A magnificent account of an ancient world in modern ferment, Thubron covers over 7000 miles in eight months enduring a near-miss with a drunk-driver, incarceration in a Chinese cell, and undergoing root canal treatment without anaesthetic, along the way.