'Zero Dark' Stars on Emotional 9/11 Connection

The true-life tale of the tracking and killing of Osama bin Laden is depicted with intensity in director Kathryn Bigelow's Zero Dark Thirty, and the ensemble drama's Jessica Chastain, Jason Clarke and Kyle Chandler explain how seeing the final cut of the film carried an incredible emotional punch.

Video: How 'Zero Dark Thirty' Copied Bin Laden's Compound

"The movie allows us to move on, I think," Chandler tells ET's Christina McLarty. "It shows us what happened, and how it went down, but it also takes a part of all of our lives this last decade. … At the very end I truly felt like I could exhale and go, 'Okay, that's over with, what's next.' And I think that's really important."

In theaters December 19, Zero Dark Thirty details the against-all-odds black ops mission to capture or kill the terrorist mastermind behind the 9/11 attacks – and the 10-year hunt to find him. Discovered in a compound in Pakistan, the Al Qaeda leader was targeted by Navy SEAL Team 6 in a deadly, high-stakes raid and killed on May 2, 2011.

"We think we know what happened, there's a lot we don't know, and you go in there with the people who do it," says Clarke of the film. "It's a very emotional piece because we're all connected to what happened in the world."

Video: 'Zero Dark Thirty' Trailer

"I was very surprised that there was a woman at the center of it all -- and then I was upset at myself that I was surprised about it," recalls Chastain, who plays the CIA analyst who anchors the hunt for bin Laden. "She doesn't have a neurosis, and she's not mentally ill. She's just capable and intelligent and she stands on her own, and I think she's a perfect representation of this generation of women. And to work on that film with Kathryn Bigelow, it's just beyond an honor.

Watch ET for more with the stars of Zero Dark Thirty…