The documentary also alleges that, years before her role on 'Homeland,' actress Nazanin Boniadi was set up as Cruise's girlfriend.

Alex Gibney’s documentary Going Clear: Scientology and the Prison of Belief, based on Lawrence Wright’s book of the same name, premiered to a packed house at Sundance on Sunday afternoon. The Church of Scientology has denounced Gibney’s documentary in ads in The New York Times and The Los Angeles Times, as well as a promoted tweet, saying the film relies on discredited sources and implying that it is comparable to Rolling Stone’s discredited University of Virginia rape story.

Below are five takeaways from the Sundance screening.

1. The Church of Scientology allegedly wiretapped Nicole Kidman’s phone. According to the film, Scientology was not keen on Tom Cruise's marriage with Nicole Kidman because her father was a psychologist, making him an enemy in the church’s view. During the marriage, Cruise distanced himself from the church, particularly when the couple moved to England to shoot Stanley Kubrick’s Eyes Wide Shut. In its effort to bring Cruise back into the fold, the church made efforts to undermine the relationship and, at Cruise’s request, allegedly hired a private investigator to tap Kidman’s phones. The church also worked to turn the couple’s son and daughter against Kidman, convincing them that she was a “suppressive person.”

2. Years before her role on Homeland, actress Nazanin Boniadi was set up as Cruise's girlfriend. The documentary details how, after Cruise’s marriage to Kidman was destroyed, the church went about to find the actor a girlfriend, alighting on a Scientologist field worker named Nazanin Boniadi. Boniadi was given a make-over – her teeth fixed, wardrobe from shops such as Burberry – for what she was told was her being elevated to work on a world stage with world figures. But it was all prep for her to meet and then date Cruise. But it didn't last. During a visit by Miscavige to one of Cruise’s mansions, the actor didn't think Boniadi paid enough respect to the leader and cut the relationship short. Boniadi then made the mistake to tell her heartache woes to colleague, who reported them to higher ups. Boniadi was punished by being forced to do menial tasks, including cleaning toilets with a toothbrush. All details are omitted from Boniadi’s IMDB profile. Boniadi left the church and became an actress. She landed on General Hospital, did a stint on How I Met Your Mother, and as the doc points out, was a key supporting player on Homeland.

3. The film suggests the church ensured John Travolta’s loyalty because it was prepared to use information gained through supposedly confidential auditing sessions to undermine him or any other member who publicly split from the organization. While the film does not explicitly state what material in Travolta’s files would have been used, it raises an implication with a shot of the cover of a tabloid newspaper purporting to reveal that Travolta is gay.

4. A former top Scientology official describes church leader David Miscavige as privately mocking Tom Cruise for his "perverted" sex life — but doesn’t elaborate. Several former officials describe Miscavige’s rise as church founder L. Ron Hubbard’s successor, and the film features abundant footage of him addressing the faithful at church gatherings. One striking example is Miscavige’s dramatic declaration of victory in Scientology’s battle with the IRS for nonprofit status, complete with a pyrotechnic display. Former church officials including Mike Rinder and Tom DeVocht then offer allegations of Miscavige’s increasing paranoia and abusiveness, recounting stories of beatings at his hands. They also describe their experiences in “The Hole,” a prison-like facility on the church’s property near the California town of Hemet, and tell how Miscavige forced them to play a crazed game of musical chairs to the tune of Queen’s "Bohemian Rhapsody." Losers were supposed to be expelled from the church, but the former members say they were so brainwashed that they fought to remain despite the abuse. Miscavige relented and let them stay.

5. The doc dramatizes how Hubbard falsely portrayed himself as a war hero to woo his second wife, Sara Hollister. But via narration of her writings, the doc shows that Hubbard abused Hollister, smacking her with the butt of a gun when he saw her sleeping with a smile on her face because he believed she was dreaming of someone else. With their marriage in trouble, Hubbard fled to Cuba with their baby daughter Alexis. He would call Hollister and announce that he had killed their daughter and chopped her into pieces, blaming Hollister for his actions. Hubbard would call later telling her the child was alive. Finally Hollister managed to flee the marriage, though Hubbard left her penniless.

6. Hubbard believed in a world much like an idealized version of 1950s America that existed millions of years ago, even with cars of the same appearance in the streets, until overpopulation led the galactic warlord Xenu to gather up souls, freeze them, send them in planes to be dropped into volcanoes on Earth and then had them blown up with hydrogen bombs, releasing their spirits into the environment and setting the stage for the evils that plague the world today.