Cinema is strewn with the ghosts of films unmade — projects that spent years in development, teetering on the brink of being greenlit before disappearing without a trace. And one such project became the stuff of legend: cult director Alejandro Jodorowsky’s planned adaptation of Frank Herbert’s classic science fiction novel “Dune,” a film which gestated in the mid-1970s and came this close to getting made.

Set on a desolate desert planet which produces a mind-altering drug that enables intergalactic travel, “Dune” cried out for an adventurous director to adapt it. David Lynch tried in 1984, and it was a disaster, but could Jodorowsky have done better? Director Frank Pavich tantalizes us with just that possibility in his wonderful documentary “Jodorowsky’s Dune,” which tells the full story of “The greatest movie never made” (as the tagline puts it).

“Once you are familiar with Alejandro Jodorowsky’s movies and then you hear that that guy’s next project was going to be ‘Dune,’ and you learn about the amazing actors he had lined up — Mick Jagger, Salvador Dali, Orson Welles — and you hear Pink Floyd was going to do the soundtrack … You wanna see that movie!” says Pavich, speaking at a post-screening Q&A at the 26th Tokyo International Film Festival

Jodorowsky rose to notoriety with the 1970 film “El Topo,” a mystical, acid-trip take on the spaghetti Western (even this description barely begins to hint at its strangeness). It blew the minds of John Lennon and Yoko Ono so profoundly that they financed its wider distribution, ensuring it became one of the first midnight movie hits in the U.S.

In 1973, Jodorowsky followed it up with “The Holy Mountain,” which was even more bizarre. But while Jodorowsky was always an underground director, he became yet more so when Allen Klein, Lennon’s manager, pulled his movies from distribution after a dispute. (Klein wanted Jodorowsky to film Pauline Reage’s erotic 1954 novel “Story of O,” but he refused.)

For cinephiles such as Pavich, Jodorowsky’s films were nearly impossible to see and they acquired a reputation as buried treasure. Pavich describes how he first saw them on video: “They were all bootleg tapes, sixth or seventh generation copies. You could hardly even see what was on the screen — garbage quality. But you got to see this alternative universe of filmmaking. What planet was this made on? It was mind-blowing.”

Pavich’s new documentary digs through the dirt to reveal the back story behind the holy grail of cult films — Jodorowsky’s most ambitious project, which had spent $2 million on preproduction and was ready to shoot before falling apart. The unmade film’s remaining artifact is a massive, lavishly-illustrated tome, which had the entire film storyboarded — nearly shot-for-shot — by Jodorowsky and his jaw-dropping, highly influential art team: British sci-fi artist Chris Foss, French graphic novelist Moebius, sci-fi special-effects wizard Dan O’Bannon and the Swiss nightmare-surrealist H.R. Giger.

The first time Pavich met Jodorowsky, in Paris, to discuss the idea of a documentary, he recalls with a laugh how “we (were) sitting across from each other in these chairs, and he put the book in between us. I think it was just to tease me, because he didn’t invite me to open it. He just sat there, knowing I was dying to look inside it.”

To gain access to the art produced for the unmade film, Pavich needed to bring Michel Seydoux — the original producer for the film — on board, but Jodorowsky hadn’t spoken to him in 30 years.

“I think he (Seydoux) hates me, because I caused him to lose all this money, millions, in the preproduction,” Pavich says Jodorowsky told him. Yet when Pavich visited Seydoux there was “Dune” artwork all over his offices, and he was eager to reunite with his old friend. An arranged meeting between the two even led to an unexpected new partnership, with Seydoux signing on to finance Jodorowsky’s next project, “The Dance of Reality” (opening in Tokyo on July 12).

While Jodorowsky’s “Dune” was never made, the book containing the film’s art and storyboards travelled widely around Hollywood, and Pavich’s documentary does a good job of detailing the many directors who cribbed from it.

“You know that ‘Blade Runner’ also comes from Jodorowsky,” says Pavich, speaking with The Japan Times. “We don’t go into it in the movie, because it’s another tangent, but without ‘Dune,’ Moebius and (‘Alien’ writer) Dan O’Bannon never would have met. And Moebius and Dan O’Bannon together wrote a comic book called ‘The Long Tomorrow,’ and it’s exactly ‘Blade Runner,’ that whole world, 1,000 percent. And Ridley Scott admits it. Every road leads back to ‘Dune.’ “

Perhaps the most delightful thing about the film is Jodorowsky himself. In an age of safe, commercial filmmaking, it is refreshing to see a director who — with a gleam in his eye — can say, “I want to make a film that will change people’s consciousness.” People don’t say that much without scare quotes around it these days, but Pavich laughs and says Jodorowsky is “a quotation mark-less person.”

The only real precedent for making a film about an unmade film was “Lost in La Mancha” (2002), which documents Terry Gilliam’s quixotic attempt to make a film adaptation of “Don Quixote.” But, says Pavich, “that’s a very sad story … he built sets, they were out in the desert shooting, and then disaster after disaster happened. That was truly a failure.”

Warming to the topic, Pavich wonders, “Was Jodo’s ‘Dune’ a failure, or was it just meant to end at that point, before the cameras rolled?

“Maybe it was supposed to end with the book and the ideas were supposed to go out into the universe and influence other things. Jodorowsky never said that he wanted to make a film, he said that he wanted to change the world, and he did. You think it would be a negative story about a so-called failure, but it’s not, it’s inspirational and uplifting!”

Of course the question remains, what if he had made “Dune,” which — with Dali’s $100,000-per-hour acting rate as an indicator — had the potential to be an over-budget, over-deadline flop, slammed for its hubris.

“If he had made it and it had been a big success, that would mean that maybe stranger movies would have become more in fashion. And if it had been a failure, it would have changed everything. There would be no science fiction movies, no studio would make them today. This was going to cost $15 million at a time when ‘Star Wars’ was half that.

“Had ‘Dune’ failed, they would have shut down ‘Star Wars,’ and you wouldn’t have had all the films that came after it. But I think the world is different because of the work he did, and it would be even more different had it been completed.”