Released in 1973, The Exorcist is a horror movie that tells the story of 12-year-old Regan MacNeil whose unusually erratic and violent behavior raises a concern.

Her mother, played by Ellen Burnstyn, seeks medical attention and when that fails, she looks to Father Damien Karras, played by Jason Miller, a Jesuit priest who confirms that Regan is being possessed by an evil spirit. To free Regan from the demons’ grasp, Karras pleads with the Catholic Church to perform an exorcism.

Despite the controversial content of the film, The Exorcist was a box office hit, and receiving multiple awards–including Oscars for Best Sound and Best Screenplay, along with four Golden Globe Awards–the supernatural horror still holds the spot for the second highest-earning R-rated horror film of all time.

It was the first major film role for Blair, whose chilling performance launched her into superstardom. Starting her career as a child model, Blair appeared in print ads and TV commercials, with credits like Ivory Soap, Welch’s Grape Jelly and Carefree Gum by the time she was only five.

As a young teen, Blair considered giving up acting to pursue a career that involved animals.

But the temptation of the starring role in The Exorcist was too much to resist.

When auditioning for the role, Friedkin instantly identified the newcomer as the perfect fit and selected her over thousands of others to play Regan.

Though it was her first major role, Blair was never coddled and expected to perform physically demanding tasks that were uncomfortable and oftentimes dangerous.

Filmed in the 1970’s, when special effects weren’t powered by technology, people were required to act out demanding parts, leaving them vulnerable to injury and illness.

In the exorcism scene–when a possessed Father Karras tumbles down the infamous steep steps to his death–a stunt man actually hurled himself down 97-steps that are featured at the end of the film.

Blair didn’t have to toss herself down any steps but the straps that held her to the bed, where she was thrashed around, dug into her back, and her bedroom, built on wheels allowing the room to actually shake, was kept at a temperature of 30 below zero so the cameras could pick up the cloud of ice when an actor breathed.

While the rest of the crew was dressed appropriately, Blair was wearing only a nightgown.

The challenges were felt by everyone on the set.

The set of The Exorcist seemed cursed and had an extensive list of tragedies and deaths related to production.

In the book, “The Fear of God: 25 Years of The Exorcist,” special effects innovator Marcel Vercoutere–the man who made Blair’s head spin–said, “There was definitely a feeling it (something bad) could happen. I felt I was playing around with something I shouldn’t be playing around with.”

One of the most bizarre incidents was when a bird flew into a lightbox, sparking a massive fire, which burned down the entire set where Regan’s exorcism was to take place. Production was stalled six weeks while the set was rebuilt.

The day before the fire, Friedkin asked technical advisor Thomas Bermingham–a Jesuit priest who guided Blatty on his book–to exorcise the set. Stating there was not enough evidence to perform a real exorcism, he instead blessed the entire cast and crew.

Still tragedy continued to strike production. Jack MacGowran, who played Regan’s first victim Burke Dennings in the film, died after getting influenza. Vasiliki Maliaros, the actress playing Father Karras’ mother, also died before the movie was released. What’s really disturbing is that both of their characters die in The Exorcist.

Other actors lost family, including Blair, whose grandfather died during production.

A total of nine people related to the production died during the making of the film.

Blair, too young to fully understand the complexity and sensitivity of the concept, was unphased by the mysterious events surrounding the making of the film.

She explained “The Exorcist was a work of fiction. I didn’t realize then that it dealt with anything in reality.”

While the idea was fictional to Blair, the religious themes were very real to some viewers, and Blair became the target of people who claimed the film was responsible for their religious crises.

She was even accused of glorifying Satan by playing Regan and received death threats.

Speaking to press was also daunting for the 14-year-old, who during press conferences, was peppered by questions from inquisitive journalists, looking for her perspectives on the movie’s concept. As Blair told Dread Central, “The amount of pressure that came down on me wasn’t anything I was prepared for. Especially all the pressure the press put on me. They thought I had all the answers about faith and Catholicism. … It was probably the most awful thing you could imagine.”

Her role as Regan, that she reprised in the 1977 Exorcist II: The Heretic, continued to haunt Blair, who had difficulty finding roles that didn’t present her as a helpless, hapless girl.

She appeared in the 1974 TV drama Born Innocent as a young girl running from her abusive family, and one year later, as the lead in Portrait of a Teenage Alcoholic.

Determined to shift industry perceptions, she appeared nude in the October 1982 issue of Oui magazine, a move that backfired, sending her career spiralling into exploitation-type roles.

Circling back to her passion before The Exorcist, she founded the Linda Blair Worldheart Foundation, a non-profit organization dedicated to rescuing and rehabilitating abused and neglected animals.