“I was the baddest-ass dude in Scientology,” declares Marty Rathbun in My Scientology Movie, a surreal documentary in which British journalist Louis Theroux attempts to make a film about the most controversial religious organization of the 20th century… only to find himself in the crosshairs when they send hostile surveillance crews out to film him right back.

Truer words have rarely been spoken about Rathbun, a devoted Scientologist for over a quarter-century who served as its Inspector General and righthand man to feared leader David Miscavige. That is, until he “blew” and left the church in 2004, thus becoming one of Scientology’s most aggressively targeted enemies.

While acting as Scientology’s second-in-command, Rathbun revealed last year in Alex Gibney’s Going Clear, he was instructed to wiretap Nicole Kidman, a suspected “SP”—or suppressive person, aka an enemy of the church—and engineer her split from the most famous Scientologist in the world, Tom Cruise. In one interview, an ex-member remembers being sucker-punched years ago during an internal church interrogation—by Rathbun, who nonchalantly acknowledges the assault when meekly challenged by Theroux. It’s no wonder he’s been subjected to one of the church’s most fervent discreditation campaigns since leaving 12 years ago. After all, as another ex-Scientologist explains in the film: “Marty knows where all the bodies are buried.”

Rathbun’s presence throughout My Scientology Movie is just one of several unconventional twists in director John Dower’s film, which premiered at Tribeca and opens on an unusual gimmick. Stymied for years in his attempts to interview members of the church, Theroux set up camp at a studio in Los Angeles and set out to understand how Scientology works, both as a belief system and an image-savvy corporatized organization, by interviewing former members, inserting himself into the process, and staging dramatic reenactments of key moments in Scientology for the camera.

He flies Rathbun to Hollywood from his home in Texas to consult and help cast amateur L.A. actors to play the elusive Miscavige, members of the church, and Cruise—part education for Theroux and his actors, part exorcism of personal ghosts for Rathbun. Along the way, Rathbun develops a complex closeness to Theroux, forging one of the more unusual and sometimes volatile filmmaker-subject relationships ever committed to nonfiction film.

The fact that Rathbun delivers that “bad ass dude” explanation while riding in the passenger seat as Theroux drives around the greater Los Angeles area, a la Comedians In Cars Getting Coffee, only adds to the sublimely Kafkaesque strangeness the film achieves with surprising regularity. That unreal edge unfolds as Theroux, filming his vehicular conversations with Rathbun on a dash cam, realizes they’re being followed by a white SUV while driving through town. Later, Scientology members pop up while the crew is out in the field, bringing their own cameras to silently record Theroux’s every move.

One of the film’s more bizarre incidents captured in My Scientology Movie happens early on, shortly after Theroux picks Rathbun up at LAX. As they stand awkwardly in a hotel room in front of a giant window overlooking the pool, a beautiful woman in a bikini coyly knocks on the door, demanding to know what they’re filming. “My name is Paz,” she eventually says, revealing herself to be Boardwalk Empire actress Paz de la Huerta in the strangest inadvertent celebrity cameo of the year. As soon as she leaves, Theroux grows paranoid.

“They sent her over, don’t you think?” theorizes an incredulous Theroux. “… Honey trap!”

Backed by the BBC and the producer of Searching for Sugarman, Man on Wire, and The Imposter, Theroux applies his immersive gonzo style to memorable effect. His British politeness and uncanny resemblance to Last Week Tonight’s John Oliver often makes for unintentional straight man comedy, particularly as he attempts to politely argue with Scientologist bulldog Catherine Frazier, who shows up multiple times with silent cameramen in tow to film the filmmakers and kick them off of roads adjacent to church grounds, and when he pushes Rathbun a little too far about his past transgressions on behalf of the church.

The film doesn’t so much raise new questions about the controversial religion as much as it illuminates the terrifying ways in which Scientology allegedly programs its converts and “defends” itself from journalists and ex-members alike. Also remarkable is how Theroux explains Scientology methodology and terms like “squirrel-busting” and “tone 40,” before agents of the church show up outside his studio to intimidate his crew using those very same tactics. But My Scientology Movie really builds toward a pointed indictment of Scientology leader Miscavige, his mesmeric control over the church’s members, and the alleged physical and psychological abuse ex-confidantes like Rathbun claim he exacted over his flock behind the ironclad walls of the church.

Given intimate access to notable former Scientologists and high-ranking Sea Org officers like Rathbun, Jeff Hawkins, Tom De Vocht, and Marc Headley, Theroux draws out the desperation it took for the onetime loyalists to turn their backs on the church—and bears witness to the intimidation tactics they deploy in front of his own cameras.

“I had to walk away from a 35-year commitment, my wife who I love very much, all of the friends I had in the world [who] were at that Int Base,” explains Hawkins, who was once married to Frazier. “A person has to be so desperate to just turn their back on everything and say, ‘I don’t care about all that—I have to leave this place because it’s just too oppressive,’ and walk out into a world that’s totally foreign, where they don’t know anybody, where they don’t know how to get a job, they don’t know how to get a bank account… you have to say, my life is over, and I’m walking out of my life into a totally different life.”

Theroux has Rathbun train their cast of actors the way the church teaches its members to aggressively confront and neg their perceived enemies, like soldiers in a psychological war. Blurring the lines between educational drill and personal exorcism, the ensemble re-creates the abuse Rathbun describes experiencing in “The Hole,” a secretive compound on the church’s Gold Base in Hemet, California. That’s where Miscavige is said to have sent dozens of senior Scientology officers for punishment and reprogramming akin to the worst corporate retreat of all time, where some are said to have spent months and years in semi-imprisonment. (The church has denied that The Hole exists.)

“It is the most destructive quote unquote religion cult I have ever read about,” condemns de Vocht, who left in 2005 after being allegedly beaten by Miscavige in The Hole. “It is a fucking nightmare… It’s a crock of shit.” Hawkins claims Miscavige “physically beat me up on five separate occasions,” including once when he attacked him in front of “30 to 40 top executives” at a meeting because he was unhappy with a script for a Scientology infomercial Hawkins presented.

Rathbun, who turns out to be a mystifying collaborator-slash-subject when it comes to his own past transgressions, remembers fleeing the church after spending just a few days in The Hole. “I thought leaving was the only thing I could do to wake [Miscavige] up. I thought because I held the keys to the kingdom, that should sober him up.”

In the end it was Rathbun who experienced a wake-up call. As Theroux and the film’s crew captures the umpteenth confrontation by uninvited Scientologists during their shoot, two of the church’s “squirrel-busters” spark Rathbun to renew his commitment to taking Miscavige down.

“I didn’t want to do it, but I’m going to have to pull the plug on this organization,” he tells Theroux. Later, when he refers to his former boss as if he’s Voldemort himself, Rathbun is a man on fire: “It’s as if he literally, in his warped mind, is begging me to end this all for him.”