There is a peculiar pleasure in watching a cinematic disaster being taken seriously. Not excused, exactly, but examined with enough curiosity to discover what might have been buried beneath the wreckage.

Few films arrive with quite the baggage of Exorcist II: The Heretic. John Boorman’s 1977 follow-up to William Friedkin’s The Exorcist has spent decades occupying that strange territory reserved for movies that are discussed almost as much for their failure as for their contents. A notorious sequel. A critical punching bag. A cinematic oddity. A film so frequently invoked as an example of Hollywood hubris that its actual ambitions can become almost incidental.

David Kittredge’s Boorman and the Devil is interested in those ambitions.

Rather than constructing another gleeful autopsy of one of cinema’s most infamous misfires, Kittredge approaches The Heretic with something considerably more valuable: curiosity. The result is a documentary about a much-maligned horror sequel that gradually reveals itself to be less interested in proving that everyone was wrong than in asking why anyone would attempt something so strange in the first place.

On paper, the sequel looked almost impossibly well positioned. Boorman arrived having already established himself as a filmmaker of considerable ambition, while The Exorcist had become a cultural phenomenon. Yet instead of attempting to reproduce Friedkin’s approach, Boorman took the material somewhere considerably more abstract.

And that, perhaps, was the original sin.

The Exorcist II: The Heretic isn’t particularly interested in being The Exorcist II in the conventional sense. It is stranger, more metaphysical and more concerned with ideas than the straightforward continuation audiences might reasonably have expected. The result is a film that can feel less like a conventional horror sequel than a fever dream constructed from fragments of mythology, psychology and spiritual inquiry.

Kittredge understands that contradiction is precisely where the story becomes interesting.

The documentary’s greatest strength is its refusal to reduce The Heretic to either of the two easiest interpretations: misunderstood masterpiece or unmitigated disaster. Instead, Boorman and the Devil allows both possibilities to coexist.

There is plenty here to remind us why the film was so violently rejected. The production was troubled, the tonal shifts were substantial and the distance between what audiences expected and what Boorman attempted was enormous. Yet alongside those failures sits an extraordinary amount of artistic ambition.

That ambition is what Kittredge wants us to reconsider.

The documentary benefits enormously from access to Boorman himself. His presence gives the film an immediacy that no amount of archival reconstruction could quite replicate. Alongside him are recollections from Linda Blair and Louise Fletcher, while contemporary filmmakers including Mike Flanagan and Karyn Kusama offer their own perspectives on the film’s peculiar legacy.

What emerges is less a conventional making-of documentary than a meditation on artistic risk.

That distinction matters.

There is something increasingly unusual about the idea of a major studio giving an established filmmaker the resources to make something genuinely eccentric. Contemporary filmmaking is hardly devoid of experimentation, but the scale at which The Heretic was allowed to pursue its particular vision feels increasingly alien.

Kittredge consequently finds something unexpectedly contemporary in a film that was once dismissed as an embarrassing relic.

Boorman and the Devil asks us to consider whether failure itself has become too threatening to contemporary filmmaking. A film that takes no risks can be competent, polished and entirely forgettable. A film that takes enormous risks can collapse spectacularly — but it can also produce images, ideas and artistic possibilities that would never have existed had everyone involved simply played it safe.

That makes The Heretic a fascinating subject not merely because it failed, but because it failed while attempting something.

And there is a difference.

Kittredge’s documentary is at its most compelling when it recognises that the history of cinema is littered with films whose reputations have changed because the cultural conversation around them changed. Sometimes reassessment reveals a genuine masterpiece. Sometimes it merely makes a fascinating failure more fascinating.

Boorman and the Devil doesn’t necessarily need to convince you that The Exorcist II: The Heretic is secretly a great film.

It only needs to make you curious enough to watch it again.

That is a considerably more interesting proposition.

For horror audiences, there is another reason the documentary resonates. Genre cinema has always been particularly susceptible to critical dismissal when it refuses to behave according to expectation. The horror sequel is expected to deliver familiar pleasures with familiar machinery. Boorman instead delivered something dreamlike, philosophical and formally eccentric.

The question isn’t whether that decision worked.

The question is whether we still value filmmakers enough to allow them to make that decision.

In an era increasingly dominated by intellectual property, established formulas and the gravitational pull of audience expectation, Boorman and the Devil becomes an accidental argument for artistic recklessness. Not recklessness without consequence, but the kind that accepts that failure is occasionally the admission price for originality.

There is something rather fitting about a documentary examining one of Hollywood’s great cinematic disasters arriving at that conclusion.

Perhaps The Heretic wasn’t a failure because John Boorman reached too far.

Perhaps its real failure was that audiences weren’t prepared for where he reached.

Boorman and the Devil doesn’t erase the film’s flaws, nor should it. Instead, it digs through the wreckage and finds something considerably more valuable than a verdict: the evidence of ambition.

And sometimes that is enough reason to look again.

SUFF #20

Boorman and the Devil screens Friday 11 September at 7:45pm as part of the 20th Sydney Underground Film Festival at Factory Theatre.

For tickets and the complete SUFF #20 program, visit the Sydney Underground Film Festival.

• Saul Muerte