In 1922, American paleontologist Roy Chapman Andrews led an archaeological expedition to Mongolia's Gobi Desert and discovered one of the richest dinosaur burial grounds in the world. Political conflicts forced him to leave before he had even scratched the surface of the treasure that lay below. In 1997, two paleontologists from the American Museum of Natural History were finally allowed to return, retracing Chapman's footsteps and unearthing some groundbreaking finds of their own. Featuring spectacular on-location footage, archival footage from Chapman's expedition and stunning computer animation, it's an incredible journey back in time to a lost world where ancient giants once roamed.