People always knew Tom Cruise was a Scientologist, but they didn’t know the extent of it. That all changed in January 2008, when a video was released on YouTube featuring Cruise in a black turtleneck proselytizing like a man possessed.

The nine-minute video, shown at a 2004 International Association of Scientologists meeting, is set to the Mission: Impossible theme and reportedly was used to attract new converts to the faith.

“I think it’s a privilege to call yourself a Scientologist, and it’s something you have to earn, because a Scientologist does,” says a committed Cruise. “He or she has the ability to create new and better realities and improve conditions.”

He adds, “Being a Scientologist, when you drive past an accident, it’s not like anyone else. When you drive past, you know you have to do something about it because you know you’re the only one that can really help.”

For the first time, people saw Cruise for who he really is.

But there’s more. In Oscar-winning filmmaker Alex Gibney’s HBO documentary Going Clear: Scientology and the Prison of Belief, in theaters March 13 (and on HBO March 29), a large portion of it is devoted to Cruise—Scientology’s most recognizable face.

The film claims that Cruise’s second wife, Nicole Kidman, was labeled a “Potential Trouble Source” (PTS) by Scientology head David Miscavige after she convinced her husband to distance himself from the faith during their marriage. And during the filming of Eyes Wide Shut, Cruise even allegedly refused to return Miscavige’s phone calls—which infuriated the Scientology chief, according to the film. So, the film claims that Miscavige tasked Marty Rathbun, formerly the second-highest-ranking official in the Church of Scientology (he left in 2004), to break up the marriage. “I was to facilitate the breakup with Nicole Kidman,” Rathbun says in the film.

Rathbun (and the film) further alleges that the Church of Scientology waged a covert campaign to split the couple, including wiretapping Kidman’s phone, auditing Cruise around the clock, and turning the couple’s adopted children, Connor and Isabella, against their mother. Cruise divorced Kidman in 2001, and then became more active within the Church of Scientology, receiving the church’s Freedom Medal of Valor in 2004.

I spoke with two of the subjects in Gibney’s film, Mike Rinder and Tony Ortega, about all things Cruise. Rinder was a second-generation Scientologist who, from 1982 to 2007, served on the board of directors of Church of Scientology International and was its executive director of the Office of Special Affairs—a self-described “fixer” responsible for putting out legal and PR fires. He left Scientology in 2007 after a dispute with Miscavige. Ortega is a journalist who’s been covering Scientology religiously since 1995, nailing several scoops while at The Village Voice. He started The Underground Bunker blog, which focuses on Scientology coverage, and is the executive editor of The Raw Story website.

There is a prevailing (albeit unsubstantiated) theory that many celebrity Scientologists are in the closet. But both Rinder and Ortega insist that this is not the case with Cruise.

“Tom’s not gay,” Rinder tells The Daily Beast. “Tom’s not gay,” echoes Ortega. “Anybody that really reports on Tom Cruise and has good sourcing will tell you he’s not gay.”

Following his split from Kidman, and his rededication to Scientology, Cruise began dating Katie Holmes in April 2005. One month later, the notorious “couch-jumping incident” on Oprah occurred. Around that time, Holmes was reportedly assigned a Scientology handler, Jessica Rodriguez (now Jessica Feshbach). Rodriguez, a high-ranking member of the Church of Scientology, reportedly accompanied Holmes on the Batman Begins press tour that summer and oversaw her interviews.

“Jessica was answering questions for Katie in interviews, and it was really, really weird,” says Ortega. “Like Nicole before her, Katie made the effort initially to become a Scientologist herself, and then escaped later.”

When Cruise and Holmes split in June 2012, tabloid reports began circulating that it was over Holmes’s fear that Cruise would ship their daughter, Suri, off to Sea Org—a hardcore, incredibly strict faction within the Church of Scientology. Rinder's parents joined Scientology when he was six, and he later enlisted in Sea Org as a teenager.

“Suri was about to turn 6, which is the age where some people start in Sea Org,” says Ortega. “That was a household where Isabella and Connor were around, and so Katie would have seen their activities in Scientology, would have seen them going for questioning, so she had a good example of what Scientologists go through. I think it did concern her that Suri was about to be the age where they were going to have to make a decision.”

Ortega spent lots of time interviewing John Brousseau, a former high-ranking member of the Church of Scientology—and Miscavige’s brother-in-law for a number of years—who left the faith in 2010. Brousseau claimed he was effectively assigned to Cruise, catering to his every whim and fancy.

“Brousseau renovated Tom’s automobiles, he renovated his hangar, he worked on Tom’s houses. There was nobody closer to David and Tom than John Brousseau,” says Ortega. “I asked him what the relationship was like, because I assumed Miscavige was star-struck and is keeping this guy. And Brousseau said, ‘You’ve got it backwards. Tom Cruise worships Miscavige like a God.’ Tom has so completely bought into the idea that he and Dave are the only big beings on Earth, and the rest of us don’t realize that we’re on a prison planet. It’s like we’re all in The Matrix, and they’re the only two people who have taken the pill.”

“That is how they think,” adds Rinder. “Miscavige isn’t holding anything over Tom Cruise. Tom Cruise is enthralled by Miscavige, and holds him in God-like status. And yes, it’s hurting his career.”

Indeed, Gibney’s eye-opening documentary-exposé may do plenty of damage to Brand Cruise, with its entire final half-hour dedicated to the actor’s alleged actions within the Church of Scientology. It will be interesting to see how Cruise responds.

“I don’t see how Tom Cruise can remain silent,” says Rinder. “I think he has got to get engaged in this, and as soon as that happens, it’s a slippery slope. Because he’s got problems. If he opens his mouth, it’s going to turn into an avalanche on him.”