Regan MacNeil

Regan Teresa MacNeil is a fictional character from William Peter Blatty's horror novel and film The Exorcist and its first sequel, Exorcist II: The Heretic. The character was portrayed by actress Linda Blair.

Casting
Regan Teresa MacNeil was portrayed by Linda Blair in the 1973 film The Exorcist and its 1977 sequel Exorcist II: The Heretic. Actress/comedianne April Winchell was seriously considered for the part of Regan MacNeil until she had developed a serious kidney infection, which caused her to be hospitalized and ultimately taken out of consideration.

Plot
Regan MacNeil is a 12-year-old girl and the daughter of actress Chris MacNeil. Regan is caught between her mother's grueling working schedule and the fact that her parents are in the process of splitting up (her father is in Europe and is not seen in the movie).

Regan finds a Ouija board game in the basement and tells her mother she has made contact with someone she identifies as Captain Howdy. Soon, however, Regan begins to act mysteriously, often violently physically striking anyone within reach, using strong profanity that surprises her mother and the doctors examining her, and several more gruesome deeds. Unbeknownst to everyone, Regan had been possessed by an ancient demon known as Pazuzu (an actual ancient Sumerian demigod). This can be concluded by the statue seen at the beginning of the 1973 film that resembles Pazuzu. Regan is also thought to be possessed by the devil himself being that when asked who she is, she responds she is the devil. Chris becomes desperate when Burke Dennings, the director of the movie she is starring in, is found dead at the bottom of a flight of stairs. The police conjectured that Burke must have been flung (with a considerable amount of force) from Regan's window, but this raises more questions than answers, since to prevent her from harming herself, Regan had been restrained to her bed.

Medical tests and examinations could find nothing wrong with her body or her mind, despite Regan bearing absolutely no resemblance to her normal self. With no help left to offer, a team of doctors (reluctantly) recommend an exorcism, conjecturing that she believes she is possessed, and this belief has caused her physical/mental change. If she believed in the power of the exorcism as much as her possession, the doctors conjectured she may become cured.

Out of desperation, Chris consults a Jesuit priest, Father Damien Karras, and begs him to exorcise (or at least examine) her daughter. Karras, going through a crisis of faith himself, expresses his belief that Regan would be better off undergoing further observation, but Chris is able to persuade Karras to come and look at Regan. Upon doing so, Karras notes that Regan's physical condition has deteriorated - her face becomes scarred, her voice becomes raspy and gravelly, she appears emaciated - but he refuses to acknowledge that a possession has taken place, he has seen this kind of thing many times before and therapy and observation is still the way to go.

As Father Karras continues to have contact with Regan, he becomes more convinced that an exorcism might be necessary after all, especially when a recording of Regan's seemingly nonsensical babbling turns out to be English, only backwards. Also, Father Karras sees the words "help me" scratched on Regan's stomach from the inside. Unnerved, he contacts his diocese, who recommend Father Lankester Merrin - the exorcist of the title and Regan's last hope.

The process of exorcising Pazuzu from Regan takes its toll on both men. Father Merrin suffers a heart attack and dies. Father Karras, his sanity destroyed after finding Father Merrin's corpse and Regan chillingly giggling about Merrin's death, willingly subjects himself to possession from Pazuzu by strangling Regan and then commits suicide by throwing himself out of Regan's window (the same way Chris' director died) upon possession.

Following the climax, Chris and Regan decide to move. Regan, whose face still scarred but healing, has no recollection of what has happened to her. But when Chris introduces her to Father Dyer, a Jesuit priest who comes to see the family off. His collar seems to subliminally remind her of the sacrifices of Fathers Merrin and Karras on her behalf and she spontaneously kisses him as a way of thanking him for saving her life and her soul.