In 1819 Alexander Csoma de Koros, a Hungarian scholar, set off on a 30-year odyssey in search of his own identity, or rather of the origins of the Magyar people. He ended up in Ladakh, where, through a bizane sequence of events, he found himself decoding the mysteries of Tibetan culture for the British government. The desire to travel, as Edward Fox so deftly illustrates, can be a terrible burden on the soul.