In the 1990s, a high Himalayan cave in Upper Mustang, Nepal was discovered to contain 42 ancient people, buried on wooden bunk beds. American archaeologist Dr. Mark Aldenderfer believes there must be more burial caves, but the challenge is how to find them deep within cliff faces in the cold and inhospitable environment of the Himalaya. He enlists the world's best technical climbers to do the searching. Aldenderfer's theory is the funerary caves were carved out by the earliest people to have settled in the Himalaya. If he can find their remains and extract their DNA, he'll learn who these people were and what brought them to the toughest parts of the planet to live.

National Geographic's cameras capture the rare moments of discovery as they unfold. First, the 7-year-old on the expedition finds a human bone along a riverbed. Then, a series of burial caves are discovered above the riverbed, with human remains spilling forth from dangerously eroding caves. Bioarchaeologist Jacqueline Eng begins laying the bones out anatomically to count the number of individuals in the cave. The climbers, led by seven-time Everest mountaineer Pete Athans, recover bones from a total of 27 individuals: adult men, women, adolescents, even infants, along with their goats, cows and a horse. Wood inside the caves provides the clue that bunk beds must have housed the bones at one time.

Film Duration: 55 min