TORONTO -- For many proud Canucks, the high-risk rescue of six U.S. citizens caught in the Iran hostage crisis of 1979 has long been known as the "Canadian Caper."

That daring operation made a hero of former Canadian ambassador Ken Taylor, who kept the escapees hidden in a riotous Tehran until they could be whisked out of the country in a joint Canada-U.S. operation.

Ben Affleck has a different story to tell.

The popcorn thriller "Argo" puts a decidedly Hollywood spin on history and the film's star and director freely admits the ramped-up drama takes some liberties with the facts.

"Because we say 'based on' -- I learned this from the lawyers -- rather than 'this is a true story,' it's understood that we're allowed to take some dramatic licence," Affleck explained during his visit to Toronto last month for the Toronto International Film Festival.

"I think there is a spirit of truth and we got really lucky because most of what happened in this movie is extremely compelling and the characters were very interesting."

Nevertheless, the question of real-versus-fake is especially acute for any Canadian who recalls Taylor as the hero of the tale, which began when Iranian militants stormed the U.S. Embassy in Tehran, taking dozens of Americans hostage.

"Argo" highlights little-known details about the escape of the six U.S. citizens, who spent almost three months sheltered by the Canadian government in Iran.

That story was declassified in 1997, revealing a risky escape plan by CIA "exfiltration" expert Tony Mendez.

Affleck stars as Mendez, who teams up with a Hollywood producer (Alan Arkin) to concoct the elaborate scheme: the six U.S. citizens are disguised as a Canadian film crew scouting locations for a fake science-fiction film called "Argo."

"Breaking Bad" star Bryan Cranston plays lifelong CIA man Jack O'Donnell, an amalgam of agency men who helped clear the bureaucracy in Langley, Va., to smooth the way for Mendez's plan.

Although O'Donnell is one of the few main characters not actually based on a real person, Cranston says he brought as much detail and back story as possible to the role.

"I went to Langley, I went to CIA headquarters and I talked to several of the officers there before we started, just to get a feel of the culture, the sensibility of these men," Cranston says in an interview.

His meticulous attention to detail included inventing a tumultuous private life that isn't even hinted at in the script, but Cranston says it added "weight to the character" by creating "anchor points" for his performance.

"I wanted to make him a devout Catholic, and I had things on my desk that weren't really seen, you know -- religious artifacts and a rosary and things like that," says Cranston, adding that the fictional O'Donnell was twice divorced and near retirement.

"It didn't make it into the movie but that's OK. It was for me and Ben saw it. If he wanted to use it he can use it."

As with any historical thriller, screenwriter Chris Terrio acknowledges that it's challenging to craft an edge-of-your-seat thriller when viewers think they already know the tale from beginning to end.

He notes that he and Affleck ramped up several scenes for dramatic effect, likening the plot to a machine that "winds everything up tight so it can be released at the end."

"You knew there was this sort of Damocles hanging over the heads of the house guests but it wasn't always an immediate clear-and-present danger that you could dramatize," Terrio explains.

"So there were certain moments when we thought, 'OK, it's not like we're lying and fabricating something that wasn't tangible in the room with these people but you can't throw imaginary stones at a character -- you have to have real stones.' And so there were times when Ben and I were trying to create real stones to throw at them so you felt the tension as tangibly as they would have felt it inside."

Cranston calls "Argo" a "beautiful script" and only has praise for Affleck's growing prowess as a director.

"He's really found himself here," he says of Affleck, whose past directorial efforts include the heist film "The Town" and "Gone Baby Gone."

"I didn't know Ben before this experience and he's a guy who knows what he wants, is very meticulous and specific in what he wants and gets what he wants without raising his voice -- without demeaning anyone, without making them feel inferior to him. And that's a talent, that's using an ability to lead and have people want to work for you and do well for you and it's a brilliant ability on his part and I think he's got nowhere to go but up."

As the rare Canadian actor in the ensemble, Garber says he felt "a huge responsibility" in portraying Taylor.

"I figured I'd be judged harshly but once I got the glasses I was fine," he said to chuckles from his co-stars, many of whom had to don unflattering dated hairstyles and clothing for their roles.

"Seriously, I didn't really know all that much because at the time I was living in New York and pursing a career and too self-involved to really get what was going on. But when I read this script, I was so astonished by this man and what he did and I thought it was beautifully written and beautifully depicted."

Taylor, himself, reportedly felt differently.

In particular, he apparently took offence to a postscript in the film that suggests the citations he received were unwarranted in light of the CIA efforts.

Taylor met Affleck following the Toronto festival, and the postscript was changed to note that the CIA "complemented efforts of the Canadian Embassy."

Despite the dramatizations, Affleck says he strove to stay true to what he felt was one of the most important elements of the tale -- the unique relationship between the United States and Canada.

"This was one moment that was a sort of clear crystallization of the best that it could be," says Affleck.

"That is accurate, that is real, that is a sort of the perfect representation of what it was."

"Argo" opens in theatres Friday