Canadian nurse Betsey Connell (Frances Dee) is hired to care for Jessica Holland (Christine Gordon), a woman on a Caribbean sugar plantation, who has a bizarre condition. The mysterious affliction baffles Betsy but when she falls for Jessica's husband, Paul (Tom Conway), she is determined to make him happy by curing his wife. However, in her quest, Betsey is drawn into the island's dark culture of voodoo and zombies and begins to uncover the Holland...