Alex Gibney's The Armstrong Lie started off as something else altogether: a celebration, not an indictment, a documentary about Lance Armstrong's 2009 Tour de France comeback try. Four years after announcing his retirement from professional cycling - a profession that had netted the Texas sports icon a record seven consecutive Tour de France wins - Armstrong was back in the race.

And Gibney, the Oscar-winning documentarian (Taxi to the Dark Side), was invited along for the ride. Unprecedented access, intimate insights, a you-are-there story. It wasn't until the following year that federal prosecutors began investigating doping charges against Armstrong. And then Armstrong's former teammate, Floyd Landis, came out with his allegations. And the United States Anti-Doping Agency accused Armstrong of taking performance-enhancing drugs, of drug trafficking.

Finally, after years of adamant denials, Armstrong went on Oprah Winfrey's show in early 2013 and 'fessed up - kind of. The millions of dollars in sponsorships were gone. Armstrong's Tour de France titles were stripped away. His hugely successful cancer foundation, Livestrong, tainted.

And Gibney paid a call, insisting Armstrong explain himself.

The Armstrong Lie, then, is a story of epic betrayal and deception - and self-betrayal, self-deception. A relentless competitor who had survived cancer to become one of the most famous athletes in the world, Armstrong was brought down by his own ego and arrogance. He had lied, straight-faced, defiant, for so long he seemed convinced he was speaking the truth. In a sport famous, or infamous, for its doping culture, Armstrong had put himself above the fray. But not only was he in the fray, he also was organizing the cover-ups, pressuring teammates, leading the pack.

The Armstrong Lie is eye-opening and myth-shattering and more than a little depressing. To watch Armstrong rationalize and compartmentalize in his interview with Gibney is maddening. Even though Gibney gets more of a "full" confession out of the man than Winfrey did, there is clearly something in Armstrong's psyche that prevents him from just laying it all out there, coming clean. Armstrong talks about the "true narrative" as though there are still extenuating circumstances, hidden facts, that justify the years of systematic doping and deceit.

An American hero, a celebrity, a legend, brought down by his own hubris. And still in denial about it.

The Armstrong Lie *** (Out of four stars)

Directed by Alex Gibney. With Lance Armstrong, Frankie Andreu, Betsy Andreu, Reed Albergotti, and others. Distributed by Sony Pictures Classics.

Running time: 2 hours, 2 mins.

Parent's guide: R (profanity, drugs, adult themes)

Playing at: Ritz BourseEndText