Miami’s 100th anniversary included a big bash on Thursday night. There was an out door concert with Barry Gibb, Sam Moore, Sheila E. and other musicians who all got proclamations from the mayor.

And guess who was honored? Famed mobster Meyer Lansky. Why should be be left out? Known through the ages for illegal gambling (the only crime was ever convicted f0r) Lansky’s pals were Bugsy Siegel and Lucky Luciano. In “The Godfather II” he was called Hyman Roth and played — for the ages– by Lee Strasberg.

Sunday night– you must watch the HBO documentary “Going Clear” about Scientology. Even knowing what I do about this cult, I was actually frightened after watching Alex Gibney’s extraordinary movie. Two hours isn’t even enough time to cover the horrors of what has gone in what Gibney depicts as a get rich quick scheme invented by a crackpot science fiction author. What you’ll see is a lot of people testifying about blackmail, intimidation, illegal surveillance, and physical violence.

But what’s most shocking is the way both Tom Cruise and John Travolta come off in this movie. Their careers could be in big trouble after enough of the public has sat down and really watched “Going Clear.” Gibney is calling for them to come clean and finally stand up to Scientology’s diminutive leader David Miscavige.

I doubt that will happen. Both director Paul Haggis and Miscavige’s own niece have said that while they were in the cult they never read any criticism of it or listened to critics. Many others who’ve left have said the same thing, including actor Jason Beghe, who saw the light and escaped in 2007.

Gibney’s film is must watch TV. For one thing, he explains how Scientology got tax free status as a religion in 1993– by suing the IRS so often and so viciously that the then chairman, Fred Goldberg, finally gave in. Gibney says that in exchange for dropping all the suits– and blackmail of IRS agents whom Scientology followed–Scientology got their status. If Gibney is right, and I think he is, we can blame Goldberg for two decades of terror. And because of the tax free status, Scientology has been able to grow to $3 billion in assets.

The movie is based on Lawrence Wright’s excellent book of the same name. Like the book, the movie hinges a lot on the testimony of two former cult members– Marty Rathbun and Mike Rinder. In the last decade they’ve each escaped and become vociferous vocal critics. This is how much Scientology and Miscavige fear these two: I was told by a journalist, who’d obviously been co-opted by Scientology, that Rathbun and Rinder were really trying to topple Miscavige so they could take over Scientology themselves. Hah! Good try, I responded. But Scientology has money to burn, and they’ve infiltrated normal people with it.

The first hour of “Going Clear” is a fascinating look at L. Ron Hubbard, the Kilgore Trout of Scientology, the cult’s roots, and several people who knew Hubbard as a fake. The second hour more fully addresses Cruise and his complicated history with wives, children and the cult. There’s also a very developed look at Miscavige, Cruise’s doppelganger and Rasputin. It’s a jaw dropper– enough so that, as I’ve said before, I doubt Cruise will ever again do business with Warner Bros., the parent company of HBO.

“Going Clear” basically claims that both Cruise and Travolta are being blackmailed by Scientology to stay in the group. You’ll see it in the film. The two stars, among the two dozen or so who’ve stayed with Scientology, participated in hundreds of “auditing” sessions in which they were taped revealing their personal secrets. Gibney and Wright say those secrets being held over their heads. Even if you’ve heard whispers of this before, the revelations now on camera are eye opening.

What’s absolutely riveting is the story of how Scientology set Cruise up with an insta-girlfriend, actress Nazanin Boniadi, who’s now on “Homeland” after a recurring role on “General Hospital.” It’s more eery than Cruise’s selection of a wife– Holmes– during casting for “Mission Impossible 3.” The story first appeared in Vanity Fair, which savaged Cruise in a detailed take down. Now Gibney has more on what happened in what could be described as its own Mission: Impossible.

What “Going Clear” doesn’t cover– Leah Remini’s exit, the disappearance of Miscavige’s wife, and about four dozen other scandals. Kirstie Alley will probably feel bad that she’s never mentioned. Neither are the misguided actors who fell for this stuff like Jenna Elfman and Juliette Lewis. What is interesting is that Scientology has not been able to attract any more celebrities. No one else has been stupid enough to fall for their tricks. I wonder if the others who are in it will wise up when they see this film.