In this powerful book, the renowned exorcist of Rome tells of his many experiences in his ministry as an exorcist doing battle with Satan to relieve the great suffering of people in the grip of evil. The importance of the ministry to "expel demons" is clearly seen in the Gospels, from the actions of the Apostles, and from Church history. Fr. Amorth allows the reader to witness the activities of the exorcist, to experience what an exorcist sees and does. He also reveals how little modern science, psychology, and medicine can do to help those under Satan's influence, and that only the power of Christ can release them from this kind of mental, spiritual or physical suffering.