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.
In 1947, having abandoned his faith, Father Merrin joins an archaeological excavation in Kenya, where an ancient church has been unearthed and something much older waits to be awoken.
Years before Father Lankester Merrin helped save Regan MacNeil's soul, he first encounters the demon Pazuzu in East Africa. Merrin's initial battle with Pazuzu leads to the rediscovery of his faith.
When two girls disappear into the woods and return three days later with no memory of what happened to them, the father of one girl seeks out Chris MacNeil, who's been forever altered by what happened to her daughter fifty years ago.