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. 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.

David, a robotic boy—the first of his kind programmed to love—is adopted as a test case by a Cybertronics employee and his wife. Though he gradually becomes their child, a series of unexpected circumstances make this life impossible for David.