William Friedkin‘s The Exorcist hit theaters in 1973 and made an impact that changed not just horror movies, but cinema itself. The demonic possession tale is still considered one of the scariest films ever made, and its story continues to inspire—genre master Mike Flanagan’s new take on the Exorcist franchise opens in 2027.

But that doesn’t mean everything associated with The Exorcist has been able to capture its success. Some have: released in 1990, The Exorcist III, written and directed by Exorcist novelist William Peter Blatty, who won an Oscar for scripting Friedkin’s film, is excellent and disturbing and well worth seeking out. The dueling Exorcist prequels—2004’s Exorcist: The Beginning and 2005’s Dominion: Prequel to the Exorcist—offer a fascinating glimpse of how Hollywood’s hunger for do-overs can manifest in freaky ways.

The Exorcist TV show, which was tangentially tied to the first movie, ran from 2016 to 2017 on Fox and delivered two genuinely spooky seasons.

But though the less said about 2023’s The Exorcist: Believer, the better, it’s still not the most notorious entry in the Exorcist franchise. That title is absolutely claimed by 1977’s Exorcist II: The Heretic, and a new documentary will explore what went wrong with a movie that must have seemed at first to be a surefire slam dunk.

As the title lets you know, Boorman and the Devil focuses on director John Boorman, who came into the project awash with Oscar nominations for Deliverance. His other credits include Zardoz, Excalibur, and Hope and Glory. But only Exorcist II: The Heretic gets mentioned in “worst movie ever made” conversations.

The sequel brought back Exorcist child star Linda Blair as a now-teenaged Regan MacNeil, elevated Exorcist supporting player Kitty Winn to the main cast, and somehow convinced Max von Sydow, whose character died in The Exorcist, to return for flashbacks. New additions included Louise Fletcher (who’d just won an Oscar for One Flew Over the Cuckoo’s Nest), Richard Burton, and James Earl Jones (the same year as the first Star Wars movie).

“After the success of Point Blank and Deliverance, Warner Brothers offered John Boorman the opportunity of a lifetime: the chance to direct a sequel to their smash hit, The Exorcist. The result was one of the biggest disasters in movie history,” reads the documentary’s official synopsis. “A critical and financial failure that not only changed how Hollywood did business but nearly ended Boorman’s filmmaking career… but to be an artist is to be a risk-taker. Now, John Boorman, Linda Blair, Louise Fletcher, Karyn Kusama, Joe Dante, Mike Flanagan, and more reflect back on the ambition of the film, the artistry and craft, and the value of big creative swings.”

Without Exorcist II, we’d be deprived of one of the greatest howlers in Hollywood history—”Come, fly the teeth of the wind. Share my wings!”—and Ennio Morricone’s actually really great film score, so for those at least, we’re grateful.

Directed by David Kittredge, Boorman and the Devil opens in New York City on August 28. It then expands to wider release starting September 4.

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