(CBR) The future doesn't look so bright in director Joon-ho Bong's sci-fi drama, "Snowpiercer." Based on the French graphic novel "Le Transperceneige" by Jacques Lob, Benjamin Legrand and Jean-Marc Rochette, the movie finds most life on Earth wiped out by an ice age while the remaining survivors have taken up residence in Snowpiercer, a massive train that endlessly circles the globe.

The elite live it up at the front of the train, the harsh conditions of the outside world a minor hiccup to their comfort, while the passengers stuck in the train's rear wallow in poverty. The underprivileged Curtis, played by "Captain America's" Chris Evans aims to change all that by claiming leadership of the back end and leading a revolt.

With "Snowpiercer" barreling into theaters courtesy of The Weinstein Company on June 27, screenwriter Kelly Masterson spoke to CBR News about climbing onboard the project, putting a fresh spin on the post-apocalyptic genre, which cut of the film will be released theatrically in the U.S. and the movie's stellar international cast.

CBR News: After "Snowpiercer" premiered in South Korea last August, how does it feel to finally have a North American release date?

Kelly Masterson: I'm absolutely thrilled to finally be getting a release date. I started on it about two and a half years ago, so it's been quite a long process. The most frustrating thing was the rollout did so well in Korea and France, and then getting rave reviews everywhere. Of course, we had the frustration over the uncertainty of what cut was going to be released in the United States. All's well that ends well. It's director Bong's cut. The United States and the U.K. are finally going to get to see this terrific movie.

To clarify, theaters will be showing Bong's original cut, and not the trimmed version that Harvey Weinstein requested?

It's the full director's cut. Director [Joon-ho] Bong stuck to his guns. I know Bong spent a lot of time talking to Harvey and talking about ideas. I know Bong came to me and asked me to write some voiceover, to see if we could mitigate some of Harvey's concerns. In the end, Bong really wanted the movie seen the way he intended it to be seen. Thank goodness Harvey is giving him that opportunity.

So much energy goes into a script and movie. How disappointing was that for you when all these discussions were happening over which cut to use?

It was frustrating. I wasn't really privy to a lot of it, so I didn't have to go through the day-by-day that Bong did. You're holding your breath. You're keeping your fingers crossed. You want the world to see what Bong created. It's frustrating, but you also feel impotent at the same time. When you're writing a script, you get to participate in all the changes. When you're at that point, after it's already in the can, there's not really a lot you can do, but hope.

The graphic novel was on Bong's radar for almost a decade. At what stage did you become involved with the project?

It's like serendipity. It's just an amazing thing that happened. Bong had seen a movie I had written several years ago called "Before the Devil Knows You're Dead," which almost has nothing to do with "Snowpiercer," except that he loved the characters. So he picked up the phone and called me out of the blue. He didn't even know me. I didn't know him. Through our agency, he got in touch with me and said he wanted me to write it. Not, "Are you interested in writing it," or "Do you want to audition to write it?" He said, "Will you write it?" I wasn't that familiar with his work. I had heard of "The Host" and "Mother," which he directed. I put him on hold for a couple of days and said, "Let me see your movies." They are just remarkable. Without even reading the source material, without reading the graphic novels, I agreed to write it because I was so impressed with him as a director. That happened two and a half years ago, and it was before he had any thinking about what he wanted the story to be. We met for the first time just a few months later in Los Angeles. He was on his way to Sundance to be on the jury there. I flew out and met him in Los Angeles. For a couple of days, we sat and talked about the characters and story and what we wanted.

With so many post-apocalyptic movies and television series, what really hooked you about this take on that genre?

Revolution. That was the big hook for me. It's so timeless. We've been doing this since the Jews leaving Egypt. We throw off our oppressors. It's common in human nature. There's a great story in the graphic novel of revolution. People trapped in a train. They cannot leave the train; they have to survive within this closed world, and yet they are oppressed, so they must overthrow their oppressors. It's such a terrific, heart-pounding linear story that you read in the graphic novel of coming from the back of the train to take over the engine. It has such force to it. That's what really excited me. The post-apocalyptic element was less interesting to me, although fascinating. The writers of this graphic novel created this whole world within this train that is beyond our time.

These types of movies often serve as a canvas for social commentary and the exploration of human nature. Were there any particular themes or ideas you wanted to examine?

Yes, all my work is always that exploration of human nature. I think it's what Bong saw in "Before the Devil Knows You're Dead," and made him think I might be right for this. I'm really interested in fucked-up people and why they make the choices they make. In this particular case, we have a very conflicted, a very dark character at the center of it that fascinated me. He's ultimately hopeful and heroic, even in the face of all this darkness. That is intriguing to me.

How much of a challenge was it to incorporate those big action sequences and dramatic moments within the confines of this enclosed space?

It's a question probably more for Bong and he certainly deserves the credit for pulling it off. As a writer, I'm limitless. Even though it's set in a train, I can still have my characters do what I want them to do. I want it to make sense, but I'm much less limited than the director is. And you're right to point out how visually remarkable it is, that he's able to do the things he does within that enclosed space. Giving him all the kudos, my job was to try to give him the characters he needed to create that. How do the characters move? There's one particular character, who is into parkour-style fighting and jumps off walls. Those were the kind of tools I was able to collaborate with him, to give him, so he could generate a lot of dynamic action within a closed space.

Did this prove to be a difficult graphic novel to adapt to a script?

I've never done it before, so I don't have anything to compare it to. The process wasn't difficult at all. We took the world created by the graphic artist and we took the central character. A lot of the rest of it was invention and jumping off what they had given us. We wanted to tell some side stories. I am always drawn to father/son stories. Bong sort of gave me free rein to write a couple of really interesting relationships that weren't necessarily in the graphic novel. That is the father-like character that is played by John Hurt, who is Chris Evans' mentor, in the back of the train. Then there's a father-like character in front of the train, played by Ed Harris.

How much license did you ultimately take with what was established on the page?

We took license with adding some rather central characters to the journey. Curtis is the main character. It is his story and that is in the graphic novel. You'll see early on a sequence about how the people in the back of the train are punished when they rebel. That is by freezing a limb outside of the train. That was an invention of Bong. We had the idea of the change that happens throughout the train as we move forward. While that is in the graphic novel, we were able to go so much further to describe what that is going to be. One of the ideas was there must be on the train all the things that you would need to survive. Water; so he built an aquarium section on the train. A garden; so there's a greenhouse. Those are all things we added along the way.

Chris Evans couldn't be any hotter right now. At the time, what were your thoughts on him being cast as your lead character?

I remember when we were writing it, director Bong said, "I love Alison Pill. I'd love to write a part for her. I love Octavia Spencer. I'd love to write a part for her." A lot of times he had people in mind. With Chris, I think it was a process where he needed to be very comfortable, so he took his time. Having seen the work, I cannot imagine anyone else in the part. Chris is really incredible. People are going to be so surprised at the depths of his acting chops. He's really quite talented.

Looking at some of the other actors, you have John Hurt, Tilda Swinton, Jamie Bell and Ed Harris. It's almost pinch-me casting.

It really is. One of the things we wanted to do is make the script about the world. We wanted to put the whole world on a train. We used to talk about Noah's Ark because it has some of that to it. It's the whole world on one vehicle, so we wanted it to be very international. As we were writing the script, we wanted an American. We wanted someone from Britain. We wanted an African. We wanted this big palette. He was able to pull together this amazing cast. I want to tell you a story about Tilda Swinton. I wrote this part for a man. We called him Minister Mason. Bong gave me a lot of leeway in writing that character. I knew it was somewhat comedic. I didn't know it was as broadly comedic, and vicious, as Tilda ended up playing it. Bong met with Tilda and said, "I'd love to work with you someday. I don't really have anything for you in this next script." He sent her the script and she said, "I'd like to play Minister Mason." We had written it for a man. Bong said, "Okay, we can go ahead and do that." But, we never rewrote it. Not even any of the pronouns. We never changed any of the "he's" to "she's." There's one scene where another character calls her "sir" and they left it in, and it works.

"Snowpiercer" opens in U.S. theaters June 27.

Copyright © 2014 Comic Book Resources. Reprinted with permission. All rights reserved.