Regan MacNeil is a young girl who is living with her famous actress mother, Chris, when Regan becomes inexplicably ill and she becomes the target of poltergeist activity. As time goes on, Regan becomes fully demonically possessed and in desperation her mother takes her to a Catholic priest who deals with psychiatric issues. Father Damien Karras has recently lost his mother and starts out not truly believing that Regan is actually demonically possessed.
Suffering from a crisis of faith, it only takes a couple of visits with young Regan for Father Karras to begin to suspect possible possession. In trying to get the Catholic Church to perform an exorcism of Regan, Karras turns to a local bishop who initially refuses the exorcism unless Father Karras can contact Father Lankester Merrin to be primary exorcist of Regan.
The doubt-ridden Father Karras contacts Father Merrin, currently on an archaeological dig in Iraq but who has begun to feel that in time, he will face an immense spiritual battle. Father Merrin returns to the United States and both priests prepare themselves physically, mentally and spiritually for the upcoming battle with something that will drain them almost to the point of death. I really enjoyed reading this book again and give it an A+!