In 1989, emergency responders received a 9-1-1 call from Maria Rossi confessing to three brutal murders. The courts found her insane, but something else found her first. Twenty years later, her daughter Isabella's search for answers leads her to an exorcism by two rogue priests, revealing that her mother is possessed by four powerful demons. Now, Isabella must face pure evil or forsake her soul. Discover why The Devil Inside is the movie critics call "evil in its purest form".