A French anthropologist named Jean Charles Pommier and his wife, Niki, move to Los Angeles, where Jean becomes increasingly troubled by strange visions and encounters with mysterious and violent figures known as the Nomads. These spectral entities seem to be nomadic, always moving, and have a sinister presence that begins influencing Jean's behavior. As he delves deeper into their nature, he begins to lose his grip on reality, causing concern among those close to him.

Anne MacGregor, a doctor who comes into contact with Jean, begins experiencing a series of bizarre and terrifying events after his death. She realizes that Jean's experiences and knowledge of the Nomads have somehow transferred to her, leading her to uncover more about these menacing apparitions and their ancient, malevolent origins. Her journey intertwines with the remnants of Jean's life, pushing her ever closer to a dangerous revelation about the true nature of the Nomads and their connection to human existence.