The Demoniacs tells the story of two beautiful women, Flavie (played by Françoise Forton) and Isabelle (played by Marie-Hélène Arnaud), who are resurrected from the dead by a group of Satanists. The ritual, meant to summon the devil, goes awry, and the two women are brought back to life with supernatural powers. As they navigate their newfound abilities, they seek revenge against those who wronged them in life.