ALEX GIBNEY fell for it, too. In 2009, as Lance Armstrong raced in his comeback at the Tour de France—vowing to do so without drugs, to disprove the unrelenting rumors of his cheating—documentary filmmaker Alex Gibney was there, rolling film, capturing Armstrong's remarkable journey. At one point in the race, it looked like Armstrong—working hard, older than his peers, determined—might win. And there was Gibney, swept up in the moment, cheering on the side of the road with everyone else.

Armstrong, of course, didn't win, and he had been cheating for years, just as he had been even as he slandered those who accused him of it. "If you crossed him, you were doomed," says one former teammate in the fascinating The Armstrong Lie, while Armstrong himself admits his arrogance: "I certainly was very confident that I would never be caught."

During the 2009 Tour, Armstrong was so confident, in fact, that he gave access and interviews to Gibney, the director of Taxi to the Dark Side and We Steal Secrets: The Story of WikiLeaks. And even from Gibney, Armstrong was able to hide his years of cheating.

So later, when Gibney—along with Oprah and everybody else—heard Armstrong admit to his years of lies, the director returned to that old footage. And he went back to interview Armstrong anew to find out how he'd been duped. These new interviews, combined with the footage Gibney shot during Armstrong's 2009 Tour, make The Armstrong Lie a portrait that's at once sympathetic and damning. While Gibney reveals how irredeemably corrupt professional cycling has become, and points out Armstrong is hardly the sport's only cheater, he also never loses sight of Armstrong as a driven, cruel, and fallible man. The Armstrong Lie captures the charisma of Armstrong and the excitement of the Tour de France, even as it reveals the hollowness within.

DEPT. OF CORRECTIONS: This article has been revised to reflect a correction. Director Alex Gibney followed Lance Armstrong on his 2009 Tour de France, not his 2010 Tour, as originally stated. Armstrong has only admitted to cheating in the seven consecutive Tour de Frances he won, from 1999 to 2005. The Mercury regrets the error, and Lance Armstrong is still a dick.