Marvel Studios president Kevin Feige may be the undisputed architect of the company’s interconnected cinematic universe, but there’s arguably no creative force that’s become more integral to its current efforts than the writing team of Christopher Markus and Stephen McFeely. After joining the Marvel family in 2011 with the first Captain America film, the duo went on to tackle Thor 2 and create the ABC series Agent Carter, before finally returning to the story of Steve Rogers with Captain America: The Winter Soldier.

That film introduced a new sense of comparatively grounded realism and political self-awareness to the world, one that bleeds through into Captain America: Civil War — and will no doubt play a part in the two upcoming Avengers sequels they’re in the midst of writing. But bringing together the disparate threads of the Marvel universe into its ultimate, climactic storyline requires a delicate dance between newly-introduced characters and long-standing favorites, all without stepping on the toes of the other Marvel films already in production. With fans already looking forward to those two big sequels, I spoke with Markus and McFeely about how they pull it off.

Bryan Bishop: I’d like to talk about Civil War just from a logistics perspective. You’ve got this huge, unwieldy cast. All these other Phase 3 movies are about to come out. How do you break the story on this thing and make sure it stays in sync with all the other projects?

Christopher Markus: Rewriting a lot. It’s a problem we will continue to have, because there’s usually three [Marvel films] going on at any one time, and it seems like we’re writing the movies where they all come together. So we do check in a lot with other franchises and say, "Hey, is there a draft, or what are you thinking?" It’s not the case where we just hide in a room and crank something out.

Stephen McFeely: It was also very important that we had a central question, a central spine that every character was operating off of. So they weren’t just off spinning in their own orbit. It was, "Everyone just enters the movie where the story requires them to." So that it is not a free-for-all.

What is the interplay between you and Marvel like? They obviously have a bigger plan for how these movies are going to play out, but I’m wondering if that becomes restrictive at all. Are they feeding you benchmark beats you have to hit, or do you have freedom to explore and play?

SM: Structure is us. That is one of our big contributions. We knew when we wanted the "splash panel" to happen. We wanted all the heroes to fight, we wanted it to be the end of Act 2, and not the midpoint and not the beginning. We are the ones that basically make those choices. Sometimes Marvel will say, "Hey, odds are we’re going to have this actor for this period of time, so probably not in every scene of the movie, keep that in mind when you’re writing it." That certainly happens sometimes.

CM: And there’s a back and forth where we say, "OK, there’s gonna be this big fight with these three people in it," Kevin [Feige] will come back and say "You know what I want to see? I want to see Ant-Man inside Iron Man’s costume," or something like that. And there will be a back and forth that way. But there’s very rarely a hard-and-fast dictate that "This has to happen."

SM: And less so all the time. We certainly had less freedom on the first Captain America. There were more dictates. But boy, the Russo [brothers that directed Civil War], we sat in a room with the Russos and a producer named Nate Moore and beat that script up for months.

There’s just an inordinate amount of characters you’re working with on this one, while still trying to give them their own story beats or moment to shine. Spider-Man has some great moments in this film, but that had been an ongoing rights issue. When did you know Marvel would be able to use him?

CM: He was in and out. There had been an early suggestion that it might happen, then it seemed to go away, and then really quite late in the process, Kevin came back in the room and said, "Guess what?" And when [Spidey] was first around, we worked out a way to use him, and when we went away, we kind of filled some of that space with Black Panther. Originally T’Challa was in the movie, but we weren’t sure we wanted to go all the way to Black Panther in the costume. When Spider-Man dropped out, we brought [Black Panther] forward, and then it all paid off, because we got an extra hero out of it. When Spider-Man came back, we kept Panther where he was, because we liked it.

What was your reaction when Kevin came into the room with that news? After all the back and forth were you bummed you had to shake everything up again?

SM: I’m always bummed, because there’s more work. But then I’m fairly excited because I think he adds a lot and I think people will be eager to see him in this context.

CM: "Honey, I can’t play with the family this weekend, but wait till you hear why I can’t play with the family this weekend! I get to play with Spider-Man!" I mean, he’s been a part of my life for a long time, so to get actually get to write scenes with him is pretty giddy.

The relationship between Steve Rogers and his best friend, Bucky, drives this movie. It’s largely based on emotion, and it feels personal. As writers, was there anything personal you two were pulling from when writing that relationship, beyond what’s already in the comics?

CM: I mean, there’s always been [the fact that] I am a bad team player.

SM: Get the quotes right! "Chris Markus says…"

CM: I don’t mean that I can’t work with others. I just mean that growing up, I never liked sports. I never liked pep rallies. I found school spirit hard to deal with. I am much more oriented towards the individual. And so there is something resonant with me about someone trying desperately to keep the team together. Maybe I’d want to question, "Why is the team so important to you?"

But you know, it feels personal every time we’re writing about Captain America because he has so little, in a weird way. I don’t mean he has so little to give, I mean just the makeup of his personality. He’s not the kind of guy who allows himself the indulgence of personal needs. So with the death of Peggy Carter — one thing that relates back to who he originally was — I have this incredible empathy [for him because] he doesn’t want to let Bucky go. Because Bucky’s it. Bucky’s the last part of the real Steve Rogers, in a way. He’s not just fighting because "This is my best friend." He’s fighting because, "I will be fully adrift from everything."

One thing that surprised me was that you didn’t nod to the big bad that’s just around the corner: Thanos. Why no teases or setups in this one?

CM: Well, I mean, he’s going to have two movies…

SM: Seriously!

CM: So we didn’t want to play him out and then have people be like, "Eh, more of this guy…"

SM: "Yet again, they gave me 45 seconds of Thanos!" That does nobody any good. The Civil War story is about this group breaking up on their own accord, and they do not need to be helped by the guy from space.

CM: We also wanted [Civil War] to be a very kind of boots-on-the-ground, grounded movie that set the stage for Infinity War, that sets all the Avengers apart from each other and at their weakest point. So that when this giant purple man does show up, they’re not ready for it.

You said the magic word there, grounded. You’ve done a very good job in making these superhero movies feel like they’re part of a recognizable reality. But as you said, there’s a big purple space guy coming in the next two movies. How do you make that work, tonally?

SM: We’ll try to split the difference. We certainly don’t want to try to betray the Jim Starlin Thanos, all those comic runs. They get pretty trippy. That’s in the DNA of it. But before we get there, you’ll see Guardians 2, you’ll see Doctor Strange. My hope is that the movie audience will be a little bit more prepared for some trippier stuff.

CM: Also, whether they’re a 12-foot purple guy, or a raccoon, or an android, they’re all people, and we’re going to write them as people. You can’t write them any other way. So, ideally it will stay grounded because you’ll completely understand why the characters are doing what they’re doing, and you will in some way or another empathize.

The Marvel Cinematic Universe, explained