In a rural corner of Louisiana, an evangelical preacher named Cotton Marcus has lost his faith. After years of practicing exorcisms, he decides to perform one last ritual, but this time with a camera in hand. With the help of a documentary crew, he aims to expose the sham of demon possessions and prove that his "exorcisms" are nothing more than magician's tricks.
The story centers around the family of a young girl named Nell, who appears to be facing a mental health crisis and exhibiting strange behaviors. Cotton arrives at the Sweetzer farm, where he encounters an atmosphere filled with fear and superstition. As he delves into Nell's situation and that of her family, he uncovers dark secrets that go beyond what he imagined.
As the day progresses, what began as a simple documentary transforms into something much more sinister. The line between reality and the supernatural blurs, and Cotton begins to question his skepticism. Unexplained phenomena and chilling events challenge his logic, leading him to a critical point where he cannot escape the forces he has been trying to debunk. Nothing is as it seems, and in an environment where faith and fear collide, Cotton is forced to confront a true horror that cannot be explained. His final experience will lead him to reassess everything he thought he knew about good and evil.