A police lieutenant uncovers more than he bargained for as his investigation of a series of murders, which have all the hallmarks of the deceased Gemini serial killer, leads him to question the patients of a psychiatric ward.
Decades before Father Merrin helped save Regan MacNeil's soul, he first encounters the demon Pazuzu in Kenya. Merrin's initial battle with Pazuzu leads to the rediscovery of his faith.