(RNS) For nearly 40 years, Hollywood has been obsessed with the possessed.
Since the 1973 blockbuster "The Exorcist" unleashed a head-spinning, pea-soup spewing, foul-mouthed and demon-possessed girl on the American imagination, a host of films featuring exorcisms have hit the silver screen.
And why not? To date, "The Exorcist" franchise — two sequels and two prequels — has grossed nearly $500 million worldwide, according to TheNumbers.com, which tracks box office receipts.
"Exorcism is Hollywood's wet dream," said Diane Winston an expert on religion and the media at the University of Southern California. "It's taking on the most fundamental questions of good versus evil and doing it in a way that's titillating and vaguely scandalous. How could that go wrong at the box office?"
The latest film to test that premise is "The Rite," which opens in theaters on Friday (Jan. 28). The film is loosely based on a nonfiction book by American journalist Matthew Baglio and stars Anthony Hopkins as an aging exorcist who may be possessed by demons himself.
Baglio's book follows the Rev. Gary Thomas, a Silicon Valley priest who was sent to Rome in 2005 by his bishop to train as an exorcist. Thomas and Baglio consulted on the film, visiting the set in Budapest to ensure accuracy.
"They were really anal about wanting the exorcisms to appear accurate," Thomas said in a recent interview. "And it is. Nothing in the movie is far-fetched, impossible, or something that hasn't already happened."
Exorcist movies have become their own mini-genre in Hollywood, said Robert Thompson, an expert on pop culture at Syracuse University, gaining a place in the horror canon. But unlike most horror movies, exorcist films possess a hair-raising dose of realism — after all, the Roman Catholic Church still performs exorcisms.
"What's so incredibly scary about exorcism is that it has the church's theological underpinning," Thompson said. "It gives the movies a sense of legitimacy, which makes the whole thing seem real."
Besides launching a genre, "The Exorcist" fixed in the public mind the Roman Catholic Rite of Exorcism as the paragon of demonic expulsion, media experts say.
"There's something iconic about the priest standing there," wearing his clerical collar and reciting ancient prayers, Baglio said. "It's not as dramatic if you just have a guy wearing a sweater and slacks in a conference room."
Baglio says film producers bought the movie rights to his book before he'd even started writing it. All he had was an outline and a few sample chapters. "How quickly it happened caught me by surprise," he said.