This review contains some spoilers:
The movie starts in Iraq, Father Merrin is on a dig when he discovers ancient artifacts.
Father Merrin leaves Iraq for America for "Something he must do". In a Classic scene when he is informing the Iraqi office he must leave a grand father clock with swing second hand stops. Creepy.
Back in the good ole US of A. The shiftiness of the devil starts. First it starts with sound in the Attic.(Which is great for me because guess what room i sleep in?). This is the beginning of crazy events yet to come. During this time the movie explorers Father Karras and his mother her illness and his struggle with his faith. Father Karras feels guilty because his mother is sick and alone in New York. She soon dies which really tears Father Karras apart. During an Exorcism all those who are taking part must have no hidden sins or guilty because the devil will try to use this against them.
Regan begins playing with a Ouija board and talking to someone named Mr. Howdy. Soon after this she begins to not be herself. Her mother takes to her to Dr. who preforms a bunch of test. Now this was a scene not in the movie when it was released in 73. The really opens up the story. In a great scene the Dr prescribes Ritalin. During a party Regan comes downstairs and tell them they are going to die up there then she pees on the carpet. Soon after the director of Regan's mothers movie is killed while watching Regan. They take regan to the Dr yet again where they tell her mother that it's a problem in her brain. After many test the Dr's tell Regan's mother that she should call a priest. You know your in trouble when Dr tell you to go to church.
Regan's mother goes to the church who sends Father Karras to investigate what is going on. He shows up and has his first talk with the posed girl. All of these scene are classic. Some of the best one liners. He soon returns for a second visit to gather proof that she is posed. Now in order for someone to be ruled as being posed them must show proof. One being speaking in a toung they have not studied or know. Also being able to tell of future events. Well Father Karras gets the proof that he needs and the church sanctions the Exorcism. They call in Father Merrin for the job since he has been through this before. They explain that he preform and Exorcism in Africa years ago that almost killed him. This of course refers to the New Exorcist movie that is out now.
Father Merrin arrives at the home and the Demon is waiting. Father Karras and Father Merrin prepare to do battle with the demon for Regan's soul. This is the strongest part of the movie. The rites are preformed on Regan and the demon is none to happy. Now during the Rites the demon begins to use Father K arras's mother death and his guilt as a weapon against him. The demon changes it's voice to sound like Father Karras dead mother which sends him to the edge. Father Merrin sends him from the room and counties on his own. Father Karras returns to find Father Merrin dead and Regan sitting on the bed. Father Karras tries to help Father Merrin but it is too late. Regan begins to laugh and this sends Father Karras into a rage. HE grabs Regan and begins to beat the ever living hell out of her. Now I am no export in this thing but I always thought that the beating came after the Hail Marys. During the beating a chain is ripped from the neck of Father Karras. At that time the demon jumps into Karras and posses him. The demon tries to kill Regan but Father Karras regains control and jumps out of the window and ends up killing himself.
This movie scares me more then any other. It created an uproar and a panic why it was released. I recommend this movie to anyone looking for a good scare.