Inside the most unnerving scene in 'Civil War': 'It was a stunning bit of good luck'

"Jesse was around," says Dunst. "I was like, 'Let's just ask Jesse to play this role.'"

"It was a stunning bit of good luck," says Garland. "That makes it sound like I'm being disrespectful to the other actor. I'm not at all. It's just the film was very lucky to get Jesse."

The climactic moment of Plemons' scene, when a truck takes him out, is triggering wildly disparate reactions. At the film's world premiere at South by Southwest, an audience in one theater gave it a roaring cheer while another theater's crowd sat in stunned silence.

As they continue on, Sammy reveals he has been shot. By the time they get to the relative safety of a military encampment of the Western Forces, he is dead. Lee later looks at her camera, seeing a photo of Sammy's body slumped in the backseat of their vehicle. In a moment of fraught tenderness, she deletes it.

"We shot that scene a lot of different ways: I don't delete it, I delete it, I was crying, I wasn't crying," Dunst remembers. "There were many different versions of that. And that's the version that Alex wanted to tell for Lee's character. So the decision was made for me in the edit because we just did a bunch of different choices."

Dunst recalls working through the emotions of the moment. "I would just put myself in Lee's shoes," she says. "If a mentor for me, if I was with them during their death — whatever that meant for me. But I think the decision for Lee was to keep that for herself in her memory. And she didn't need a photo. It'll be a photo in her brain for the rest of her life."

In an early scene in the movie, one of the first pieces of advice that Lee gives to Jessie is to wear a helmet. And during a firefight early in the film, Dunst, Spaeny and Moura are indeed all wearing helmets. But then they never wear them again, even during the climactic military attack on the White House.

"We're just saying we lost them," explains Dunst with a knowing smile. "That was a big debate, believe me. And I don't know how much I should share, but basically, for cinema, we weren't totally sure if you wanted to see your characters through the whole movie in helmets.

Dunst says she thought she looked like Goldie Hawn in "Private Benjamin" when wearing her helmet. Spaeny had concerns of her own.

"You can't see my eyes," says Speany, with a small laugh. "It's realism until the point you can't see my face."

Part of what makes "Civil War" so powerful is how plausible it is, depicting people in rare moments at their best but more often at their worst, riven by self-interest and small-minded fears. The film's bracing sense of reality also leads to a deep concern for these journalists urgently heading toward danger, helmets on or not.

"It was a cinematic choice with that one," Dunst says. "I feel like in every other thing, we tried to make it as real as possible."