Set during the Cold War, the Soviets – led by sword-wielding Irina Spalko – are in search of a crystal skull which has supernatural powers related to a mystical Lost City of Gold. After being captured and then escaping from them, Indy is coerced to head to Peru at the behest of a young man whose friend – and Indy's colleague – Professor Oxley has been captured for his knowledge of the skull's whereabouts.