And some of that wouldn't have made it into the film if the Universal flick — based on the graphic novel The Coldest City — didn't take some creative liberties.

The film and graphic novel follow badass superspy Lorraine Broughton (Charlize Theron) in 1989 Berlin as she fights to protect the secrecy of a list of other agents.

While the main focus in both the graphic novel and the script was always on Broughton, in the film some of the minor characters got a lot more attention than originally planned, including that of Sofia Boutella's Delphine Lasalle.

Long story short: She was originally a male character. In the graphic novel, Lorraine is shown seducing him (both characters are clothed), but you don't see any sex. The film's writer, Kurt Johnstad, cites a conversation he had with Theron that changed that.

"In the graphic novel, the Lasalle character, the French agent, is actually a man. I said, 'I think it's cool if we gender flip this and make it a woman,'" Johnstad tells Heat Vision.

Theron's response? "She was like, 'That's cool.'" The relationship between the two stars has also driven the studio's marketing campaign. In the trailer the sex scenes between the characters play a major role.

On whether or not the duo's relationship would have been as involved had Lasalle been a male in the film, Johnstad quips, "We were able to develop the characters a little more. It's all there. We're pushing the envelope. Maybe people watching it are comfortable with that or maybe it makes them uncomfortable. And that's good."

Says the film's director, David Leitch: "The relationship was flipped before I came onboard. It was a great idea. You always have to find ways to contemporize these stories, reach bigger audiences and be provocative in your storytelling."

In the film, when Broughton isn't kicking ass, chain-smoking, on a mission to find her enemy or surviving an underwater car crash , her relationship with Lasalle is what shows her more vulnerable side.

"We furthered that narrative between them and really tried to use her as a way to show Broughton's humanity," says Leitch. "The Lasalle character represents naivety and innocence that Lorraine has obviously lost. For a moment she cracks and shows humanity in a world of lies where you really can't trust anyone. She was a really important part of the story so we expanded that a bit."

Another change from the source material is the possibility of a sequel. With its cliffhanger ending, the film may earn a part two, depending on how it performs at the box office (early projections see it raking in north of $20 million domestically). Theron teased to Heat Vision, "We're starting that conversation now. We're definitely talking."

Atomic Blonde is in theaters nationwide.