Perfectly preserved 3000-year-old mummies have been unearthed in a remote Chinese desert. They have long, blonde hair and blue eyes, and don't appear to be the ancestors of the modern-day Chinese people. Who are these people and how did they end up in China's Takla Makan desert? NOVA takes a glimpse through a crack in the door of history, to a past that has never before been seen outside of China.