Isabella Rossi travels to Rome to uncover the truth about her mother, Maria. Many years ago, during an exorcism ritual, Maria killed three people and was declared criminally insane. Her daughter wants to find out if her mother suffers from a mental disorder or if she is truly possessed by demons. Isabella hires two young priests who use modern methods to fight evil spirits. During a secret ritual, the characters encounter an incredible evil that begins to threaten their lives.