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The plot line was going to be nothing short of epic: A cancer survivor, hounded by detractors, does the impossible – returns to the sport he loves and proves them all wrong.
That's the film that director Alex Gibney was making in 2009, about Lance Armstrong's heroic comeback to the world of cycling.
But the project came to a screeching halt when the doping scandal finally consumed the sport's biggest star.
Then, after Armstrong finally confessed to his sins, Gibney reopened the project, and what began as a fan film turned into an unflinching look at a spiraling web of lies.
"The fury that served him very well on the bike, turned out to be very damaging off the bike," Gibney said in an interview with CNN's "The Lead with Jake Tapper."
Armstrong told a story that was bigger than it needed to be, said Gibney.
"He would always say, 'How dare you say that I, as a cancer survivor, would ever use performance enhancing drugs,'" said Gibney.
"The enormity of that miraculous story if it were true, came crashing down on him, because so many people were pissed off," said Gibney.
The film makes a clear case that Armstrong would have gotten away with it all, if he hadn't returned to the Tour de France in 2009.
"That's the mystery that haunts the story," said Gibney.
For more of our interview with Alex Gibney, check out the video above.