[Editor’s note: The following contains spoilers for Biosphere.]Directed by Mel Eslyn, who also co-wrote the script with Mark Duplass, the part sci-fi, part comedy, all very unexpected flick Biosphere finds lifelong best friends Billy (Duplass) and Ray (Sterling K. Brown) living in a dome as the last two men on earth. Being a scientist has helped Ray in keeping them both alive while the hostile planet outside can no longer do so, but life and nature can be very unpredictable, and you must quickly learn to adapt, if you want to survive.

During this interview with Collider, co-stars Duplass and Brown talked about the weird impulse that led to the existence of this project, what they both enjoyed about working with Eslyn as a director, the importance of not only finding the right actor but the right human being to play Ray, the movie’s Super Mario Bros. argument, and why they worked extra hard to get the tone of the material right in post-production. They also talked about what a season of Room 104 (Duplass’ HBO anthology series) centered around Brown could look like, if they were to ever get the chance to do it.

Collider: I’ve seen this movie and have been changed by the experience, so thank you very much for that. I love having an experience that I never could have expected or imagined.

MARK DUPLASS: That’s wonderful.

Image via IFC Films

Mark, how did this come about? What was the initial idea that all of this grew out of?

DUPLASS: It was just this weird impulse I had, that I wanted to see these two guys living inside of a dome, arguing fiercely about Super Mario Bros., in ways that were way more serious than it should be. But I didn’t really have the story and the breath of it. So, I started chasing it and following it, and it started to become clear to me that this was gonna be a story that dealt with some of my own issues growing up, as a Southern male who was told that we were the elite and we were meant to lead with confidence and vigor. I’ve been unwinding that slowly, throughout my life. And so, I explored that until I hit a little bit of a dead, end and then I brought it to Mel Eslyn, who brought her experience as a science nerd and as a queer woman and her perspective. And then Zackary Drucker, our creative producer, brought her perspective as a trans woman. And then when we brought it to Sterling [K. Brown], he had all these wonderful ideas about things he’s dealt with, as a Black man growing up in St. Louis and the homophobia he experienced there, in and around the church. There was this wonderful soup, where all of us could bring a little something to it. And I loved the idea that we could make people giggle and have fun, and also do some of this other stuff. I thought that would be great.

Mark, as someone who’s worked with Mel for a number of years, what most impresses you about her and her approach to it all, having seen her grow over the years? And Sterling, as someone who hadn’t worked with her before, what most impressed you about her?

STERLING K. BROWN: I was shocked she was a first-time director. Really, she had such a handle and command of the material and her vision that there was no hemming and hawing. There was clarity. There’s a hive mind that happens at the Duplass Company too. They’re all, “The best idea wins,” and everybody works as a collective. It’s a very borg, “Resistance is futile,” thing. I felt like I was in capable hands. At no point in time was I like, “Does this first-time director know what they’re doing?” No, never, not at one point in time, throughout the whole process.

DUPLASS: For me, the thing that is always striking to me about Mel, even though I’m working with her day in and day out, and she’s been running my company for 10 years, is her extreme adaptability and the speed with which she evolves, as a creator and as a human. A lot of times, when I’m making something as a director and I show a rough cut to someone or I send a first draft of the script, I get hit with notes, they bruise my ego, I get defensive, I get mad at my friends for a couple of days, I go through some exercises, and it takes me a couple of weeks to get back up and learn and figure it out. Mel’s super processor of a brain and heart is able to say, “I believe these people are only here to help me with these ideas.” That lack of ego on such an inexperienced relatively new official director, even though Mel has been deeply creatively involved on with our creative producing for years, it never fails to impress me.

Sterling, did you know everything about this story before you read the script, or did you go into reading the script completely cold?

BROWN: Pretty cold. I think my manager or agent had read it and they said, “So, take a look at this. There’s this new Duplass brothers movie. They take some pretty big swings. It may or may not be up your alley. So, read it and let us know what you think.” Sometimes when they read it first, they’re like, “This is probably a pass.” But with this one, I was curious because they wanted to see how I would respond to it. So, I read it and I laughed from beginning to end. And then, I cried at the end of the movie. When I got to the crux of the film, I was like, “Oh, my goodness!,” and I clutched my pearls. And then, I asked myself, “Can you do it, bro?” I thought about the total scope of what the movie was trying to say, and the love with which it was made, and I was like, “Of course, you can do this. This goes right with your desire to just love without limits.” The movie is so beautiful and so full of magic that whatever minor trepidation that I may have had, I was like, “I can push that aside and go make a beautiful piece of work with a beautiful human being.” It was great.

Image via IFC Films

I had the funniest moment watching this because I was ready to cry early, over the fish. I was like, “Oh, my God, the fish is gone! Is the movie over? Are they going to die already? How is there going to be more of a movie? How can they go on?”

DUPLASS: You had what I like to call the Stripes experience. Remember the Bill Murray movie Stripes, where the movie ends at minute 80, when they get the military performance right, and then there’s this whole other movie where they get into a Winnebago and go across Russia’s lines.

BROWN: I call that the Full Metal Jacket experience. It’s the same thing.

Mark, it sounds like, not only did you have to cast an actor, but you also had to cast a human being because there’s only so many people you could give this material to and know that they would do it. So, what was it about Sterling?

DUPLASS: You just nailed it. Not only do we have a very strict, “We don’t work with assholes policy,” so I’m always casting humans along with actors, but more than ever, with this movie, was that the case.

BROWN: Good policy.

DUPLASS: I knew I was a fan of his work. I saw what he could do. I talked to Sarah Paulson about him. I vetted him. But I also watched a lot of interviews with him, and I watched his way. I watched the way he talks and could see the deep humility, the big sense of love, the bigheartedness, and the goofiness that he could bring to it. It was like, “Oh, man, these are all the things swirling around.” And then, we met and realized that we’re the same age, we’re both married to women who are actors and filmmakers, we both have two kids, we’ve both been in this industry forever, trying to find our work/life balances. We both grew up in conservative areas at the church and what that did to us, as men. It felt very spiritually correct.

Mark, is this whole Mario/Luigi argument something that is a conversation you’ve been having in real life?

DUPLASS: No, I just came up with it one day. But what I didn’t realize was that what I was doing was dealing with a lot of elements that I deal with in my own life, being in deep collaboration with my brother Jay, and being seen as two faces of an operation, also with Mel, who runs the company, and her taking a less visible role in how creatively involved she is in everything we do, and me having some guilt about that and wanting her to have more visibility, and giving that to her on this very project, as writer and director. All of that stuff was the soup that we were trying to cook up.

BROWN: You reminded me of something when we were shooting the film, which is that you take turns with people, as far as who’s out in front. In any partnership or relationship, especially with us being married, there are times when my wife will tell me that only one person gets to be the star in a relationship. I said, “Why is that Ryan,” who’s my wife. And she said, “That’s just the way it is.” I said, “Who’s the star in our relationship?” She goes, “Well, you are, Sterling.” I said, “Why is it me?” And she goes, “Because everybody loves Sterling.” And then, it became this moment where I was like, “Okay, I’ve gotta make sure my wife knows that she shines as bright as anybody else.” So, there are moments where you play the foreground or the background, just understanding what that relationship means, at that particular time. I think the Mario/Luigi thing encapsulates that.

And that is why you are still married.

BROWN: Sometimes you’ve just gotta play the tambourine, baby.

Image via IFC Films

You guys obviously had fun with this and you clearly have fun with each other, but when you’re the only two people in a movie and you’re stuck in the same location for the duration of it, did you ever have a moment where one of you just wanted the other to go away?

BROWN: No.

DUPLASS: No, I never had that. If anything, I was knocking on Sterling’s door a little bit. Bo Burnham’s Inside had just come out, and we were like listening to it. We were honestly looking for more of that. He had to go memorize the script. I had been sitting with it for about two years, so he got space on that. But I never felt that. Part of that is there’s only a certain kind of person who’s gonna say yes to this movie, for the amount of money we’re paying and for the subject matter.

BROWN: I made a ton, what are you talking about?

DUPLASS: It’s natural selection, in that regard. Only a certain kind of person is gonna walk through that door anyway.

BROWN: We had a great time. There was not a moment, during shooting, where I felt like, “I can’t believe I’m here again.” I was like, “I’m so thank thankful to be here.” It wasn’t just Mark. The whole crew had an incredible vibe and such a desire to bring the story into existence. It meant something to everyone who was there, and that feeling just infused you even more, as you went through each day.

DUPLASS: Yeah.

There is definitely some delicate subject matter in this. You want it to be funny, you want it to be awkward and uncomfortable, and you want to get a reaction, but you don’t want to just be silly. What was that tone like to find? How tricky was it to figure out, if you were going too far?

DUPLASS: Without getting too much in the weeds, the essential recipe for that is to play the truth. It sounds like a platitude, but it really is true. Certain scenes that we wrote felt funnier on the page than when they came across, and we tried not to roll with that. We tried to trust that our instincts and our internal tonal navigators were telling us to go that way, so we trusted that. And then, beyond that, it was a rigorous testing process with this. And when I say testing, I don’t mean putting it up in front of a theater of 300 people to score it. We brought in our deepest and most trusted collaborators and said, “Hit us hard. Where are we getting this right? Are you seeing any insensitivities here? Are you seeing any blind spots? What are missing?” We’ve never worked over a movie so hard in post-production.

Image via IFC Films

Mark, having worked with Sterling, if you could create an episode of Room 104 for him, what genre would you like to see him in?

BROWN: That’s an interesting question.

DUPLASS: The first thing that came to mind for me is that, if I had a Season 5 of Room 104, I would create 12 different episodes with Sterling at the center of each of them, all playing wildly different and challenging things. He could do all the different things I’d want to see him as, and the first one that I’d definitely wanna see is a closeted priest.

Sterling, do you feel like you have a character that you would add to that mix?

BROWN: Oh, my God, I love that. A closeted priest? I’ve never thought of that. That would be so much fun. What else would there be like? There are so many different things that I am drawn to. Right now, in my life, I’ve played a girl dad on TV, but I have boys in real life. [Mark] has a 15-year-old and an 11-year-old, and I’m very curious to see what my boys are like, as puberty transpires. My pop passed away when I was 10, so in the first 10 years, the blueprint was set, but beyond that, I’m starting to enter into unexplored territory. I’m curious, as my oldest gets a little bit older, boys have this tendency to withdraw a little bit, and I’m catching myself in these moments of, “He needs his space, but don’t give him too much space because you want him to know that he can always come back.” So, a teenage boy dad is something that I’m intrigued by because I know it’s on the horizon.

DUPLASS: I love that. Playing something that you can’t see yet sounds really cool

BROWN: Yeah.

I feel like now I need all of this to happen.

DUPLASS: Like all those seasons of shows, like Law & Order: SVU, now we need Room 104: SKB.

And I would be the first one watching.

BROWN: God bless you.

Biosphere is in theaters and on VOD.