Father Gabriele Amorth, the Vatican's chief exorcist, has spent his life fighting demons. But when he's called to investigate a young boy's terrifying possession, he realizes that the devil's work goes far beyond religious superstition. Uncovering a centuries-old conspiracy that the Vatican has desperately tried to keep hidden, Father Amorth must face his own mortality and decide if he can continue to stick to his faith in God whilst battling evil.