In 1999, seasoned explorers hauled GPS gear into the mountains of southern China to find a valley everyone knew was invented by a British novelist. This deep dive traces Shangri-La from James Hilton's 1933 novel Lost Horizon, with its lamasery and slow-aging inhabitants, back to the Tibetan Buddhist concept of beyul, hidden sanctuaries established by Padmasambhava to preserve wisdom during times of conflict. Hilton, who never visited the Himalayas, built his valley from British Museum reading and the 1840s travelogue of French priests Huc and Gabet.

The episode follows the real expeditions that chased the fiction, including Ted Vaill and Peter Klika in Sichuan's Muli region, Laurence Brahm in Yunnan, Michael Wood's search for Tsaparang, and Josh Gates in the sky caves of Lo Manthang, all of which missed Hilton's own statement that the valle ...