In 1929, fossils of an ancient human ancestor are uncovered in a cave in China. Ahead of a Japanese invasion, scientists entrust a footlocker containing these fragments to US Marines who are later captured. As the 'Missing Link' vanishes, strange testimonies, cloak-and-dagger meetings, shipwrecks, and suspicions of treachery all lead to dead ends. Will we ever recover the remains of Peking Man?