Stephen Lane is mystified by his wife Juanita's coldness toward himself and their daughter Nancy. Juanita, who was born and reared on the island of St. Christopher, located near Haiti, is obsessed with the drum beats of her native land, and so Stephen sends her to a psychiatrist. Juanita is diagnosed as having a neurosis, and when she demands to return to her home, Stephen acquiesces, although he insists that she take along her secretary Gail to care for Nancy. Macklin, the overseer of Juanita's uncle's estate, visits her and begs her not to return to the island, for he knows that as a child she was initiated into voodoo rituals and was elevated to a prominent position within the cult. Juanita refuses to listen, and when Macklin threatens to go to Stephen and expose her, he is killed by the native who accompanied him. Juanita is happy to be back in St. Christopher, but gradually becomes more cruel toward Nancy. Juanita's uncle, Dr. Perez, warns her to avoid becoming involved with voodoo again, but she arrogantly ignores him. Worried about Nancy, Gail sends for Stephen, and after her message is sent, the radio operator is murdered. By the time Stephen arrives, Nancy's nurse has been killed and Juanita has begun behaving even more strangely. While the drums beat one night, Juanita disappears, and Lunch, a kindly black, leads Stephen to a voodoo amphitheater in the jungle. There Stephen is horrified to see that Juanita is high priestess in a cult of human sacrifice, and he shoots a priest in order to prevent the murder of a girl. He also learns that all of the whites on the island are to be murdered except Juanita. Perez, Nancy and Lunch flee to Perez's home, a portion of which is fortified. Juanita leads an attack, but Perez, Gail and Stephen escape to Perez's yacht. Nancy, however, is taken to be sacrificed by her mother. Stephen follows her into the jungle and kills Juanita, then flees the island, engulfed in slaughter, with his daughter. As she follows on another sailboat, Gail realizes that Stephen loves her and that she will be able to take the place of Juanita in his heart.