New York police officer Ralph Sarchie (Eric Bana), struggling with his own personal issues, begins investigating a series of disturbing and inexplicable crimes. He joins forces with an unconventional priest (Edgar Ramirez), schooled in the rituals of exorcism, to combat the frightening and demonic possessions that are terrorizing their city. Based upon the book, which details Sarchie's bone-chilling real-life cases.