Superheroes, all-encompassing CGI, in-your-face 3-D effects — these are the predominant trends in this year's summer-movie season. What a surprise, then, to find "Knight and Day," an action flick not based on an existing entertainment property, one not shot within the confines of a green screen and one featuring an actor who's a member of that increasingly rare breed: the traditional Hollywood movie star.

The movie, in fact, has as much in common with old-school pictures like "North by Northwest" and "Charade," and for two hours, its stars (Tom Cruise and Cameron Diaz) are more reminiscent of Cary Grant and Audrey Hepburn than other contemporary film stars.

Director James Mangold recognizes the throwback factor to "Knight and Day" — and, as the guy behind heady fare like "Cop Land" and "3:10 to Yuma," he welcomes it — but that's not what pulled him into the production. Rather, it was the chance to work with Cruise and Diaz.

"When I first read it, I thought it was a really promising idea for a movie, very charming idea for a movie," Mangold told MTV News. "But what really intrigued me was that Cameron was attached — she's someone who I adore and have known for a long time — and Tom was curious about it.'

Mangold had met with Cruise around the time he was developing "Yuma," but both men agreed the actor wasn't right for the film. When they did end up working together, they wanted it be on something that wasn't so damn serious.

"There was a lightness to him and a charm to him," Mangold said of Cruise. "I hoped he'd make a choice to make a picture that exploited that even more. This was a really great opportunity, I think, for him to shine, still being the leading man and still being capable but getting that other side of him out."

That's exactly what he does in "Knight and Day," ditching the solemnity of his characters in films like "Valkyrie" and "Collateral" and returning to the type of manic comic territory he explored in "Jerry Maguire" and "Risky Business."

Once Cruise signed up, the script began to change. The story went from a comedy vehicle to something that merged high-octane action with comedic jabs. And the film continued to morph even as filming was under way.

"There were days we'd show up and we'd completely rewrite what we were doing while we were going it," Mangold said. "There's a lot of jazz to Tom."

Check out everything we've got on "Knight and Day."

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