An island paradise home to a desolate prison and an abandoned system of caves for a secret society contain a haunting past; experts investigate the evil secrets behind these deserted places to uncover how they were built and why they were abandoned. This is a mashup of S05E08 "Curse of Satan's Catacombs," S07E03 "Secrets of Mafia Island," and S01E02 "Curse of Hell Island."