Mustang, a walled former kingdom in the Nepalese Himalayas, holds Buddhist cave temples whose murals have survived for centuries in near isolation, and this NOVA episode follows the conservators sent to keep them from crumbling further. The paintings, some dating back to the fifteenth century, cover cave walls carved into cliffs that are themselves eroding, so the restoration work doubles as a race against the landscape. Conservationists clean soot and salt damage from the plaster, stabilize flaking pigment, and photograph iconography that has rarely been documented, working in caves reachable only by ladder and rope. Local monks and villagers appear alongside the outside experts, since the temples remain active sites of worship rather than museum pieces. The film stays close to the physical labor of preservation, mixing paint, testing adhesives, and debugging what centuries of smoke and weather have done to the images. What emerges is less a survey of Tibetan Buddhist art than a record of the specific, patient work required to keep it from disappearing.