Fact-based drama, set in 1910 Milwaukee, about an older married woman, bored with her husband, and her dead son's friend she takes as a lover and hides in her attic over the next two decades -- an affair that ends in murder.
Katie and Guy take a sea cruise in their sailboat and discover a couple on a wrecked boat, victims of a brutal attack by their crew. They take Eliza and Nick on board. The new boarders appear nervous about returning to Honolulu, and when the boat's engines die and other little incidents occur, Katie and Guy start wondering whether the shipwrecked couple are what they appear to be.
When a dark force begins to destroy a couple's happiness, they decide to turn to a parapsychologist who discovers that the husband is possessed by a demon.
