China's Secret Mummies

In a remote Chinese desert, archaeologists have unearthed mummies that are thousands of years old, many with Indo-European features such as blond hair and blue eyes. Where did they come from? Dr. Spencer Wells, National Geographic explorer-in-residence and director of the National Geographic Genographic Project, goes on a mission to use advanced technology to decode the genetic identity of these unusually well-preserved mummies and open a unique window into the ancient migrations of mankind.