"Are you punishing Regan?" Yes.
"You wish to harm her?" Yes.
"To kill her?" Yes.
"If she died, wouldn't you die too?" No.
I would like to start by saying two things:
1. I have never seen the movie and have no idea how the novel compares with the film.
2. Do not read this book before bed, unless you're the kind of person that enjoys sleeping with the lights on.
The story opens with Father Merrin, who is working on an archaeological dig in Iraq and is overcome with a feeling of foreboding as he discovers a statue of the wind demon, Pazuzu. Miles away, in Georgetown, Washington DC, Chris MacNeil is finishing up the filming of her next movie with director Burke Dennings before going home to her daughter, Regan. A normal life in the day of an actress except for the Jesuit priest watching the performance; Father Damien Karras. And it quickly becomes clear, that everything is not normal.
Chris's Regan is developing behavioral problems; waking up terrified during the night and spending her days talking to imaginary friend, Captain Howdy through a Ouija Board. Father Karras, who is new to the area and an expert in Black Masses with a degree in psychiatry, is questioning his faith after the death of his mother. After his church is vandalized, his superiors suspect that he may have done it himself and have him transferred to a less stressful job. As Regan's problems increase from overactive imagination to violent outbursts and psychokinetic phenomena, Chris seeks out medical help. The doctors have plenty of theories, it could be physical, it could be psychological, but they can't prove anything. As if Chris and Father Karras didn't have enough problems, Detective Kinderman won't stop asking questions nobody wants to answer.
I think this story was perfectly terrifying. Chris Macneil, is facing down a problem she isn't equipped to handle. So many doctors are willing to write off her daughter's behavior as mental illness... A mental illness they aren't sure how to name or treat. Chris is surrounded by people who want to help, but at the same time she's fighting all alone. It's her who has to care for Regan, no matter how repulsive her daughter gets, and it's her who believes that Regan's problem is supernatural not psychological. And Regan isn't just a little creepy, she's downright sleep-with-the-lights-on-disturbing. Incredibly strong, violent, angry, murderous, verbally and physically obscene, disgusting, and a whole bunch of other adjectives not normally associated with a little girl. Regan isn't just a parent's worst nightmare; she's everyone's worst nightmare.
I love the elements in this story; it's more than Good vs Evil. It's a little bit of Science vs Religion and Believers vs Non-Believers and mostly a giant test of faith. Chris Macneil is an atheist; she doesn't believe in God but her daughter's affliction is enough to make her believe in the Devil. Father Karras believes in God, even though its harder some days than others, but he can't bring himself to believe that Regan is truly possessed. Bringing important questions to the light: How can you fight something you don't believe exists? How can you truly believe in God/Satan, if you don't believe in his counterpart? And how can Regan be saved, if you can't identify what's wrong in the first place?