Husband and wife anthropologists Phil and Emily Epp have not been the same since they spent time with a native culture that believed they could absorb a person's soul by inhaling their dying breath. In a freak accident, Emily is given the tribal leader's dying breath, which changes her and her husband forever. The two, along with the tribal leader's youngest son, set out to capture all the dying breaths they can, enabling them to live forever (or so they think). They end up on the island of St. Luke, where they kill islanders by cutting off their right hands. They get away with it for years until a few of their victims wash up and the local police realize they have a serial killer they dub "The Machete Man" in their midst.