'Avengers: Endgame' Screenwriters Talk Multiverse, Manifestos, Time Travel And More Spoilers

Avengers: Endgame: Infinity Money: No More Pee Breaks has been the number one movie in the country for the last three weeks since it was released, making over $700M domestically (and around $2.5B globally). It's been a hit with audiences and critics (though there has been some controversy over a few things, like Thor's physical transformation and Black Widow's ultimate fate). It is a movie that is made up almost entirely of hilarious callbacks, insanely-detailed Easter Eggs, and gratifying payoffs for the entire series: emotional payoffs, comedic payoffs, character payoffs, and especially, the payoffs that Robert Downey Jr. will be living off of for the rest of his life.

Two of the people most essential to its success are screenwriters Christopher Markus and Stephen McFeely, who have a long and illustrious list of MCU credits. They have previously written all three Captain America movies, Thor: The Dark World (they've noted in interviews that they "came to help out" on that script), created the TV series Agent Carter and wrote both Infinity War & Endgame. When they were hired in 2015 for this two-part project, they created a 60-page document mapping out tons of possible ideas on how to end the 11 year, 22 film saga. Those ideas ended up becoming the foundation for everything in the films.

They've given more than their fair share of interviews in recent days explaining how they chose who would die, rejected ideas, the final battle, and more. I met them when they appeared on All Of It a few weeks back, which resulted in us sitting down to speak about all things Endgame last week. The interview below was edited and condensed for clarity.

OBVIOUSLY THERE WILL BE SPOILERS FOR THE ENTIRE FILM

(Note: I tried not to hit all the exact same questions they had already been asked a gajillion times, in case you're wondering why we didn't talk about Iron Man's arc or Cap's ending...I do wish I had remembered to ask them whether it was a big deal that so many humans held Infinity Stones in their hands after it was established it was a really big deal in Guardians Of The Galaxy, or why in episode 2F09, when Itchy plays Scratchy's skeleton like a xylophone, he strikes the same rib in succession, yet he produces two clearly different tones. C'est la vie!)

Stephen McFeely (L) and Christopher Markus (R)

To start: something you mentioned on WNYC is that neither of you were big comics fans or readers while you were growing up. Do you think that not being as emotionally invested in the comic book world initially gave you some added perspective or benefits in making the films?

Christopher Markus: We certainly became emotionally invested as time went on, but also not being textbook rabid fans who knew every in and out of the comics gave us sufficient distance to figure out a new arc for the characters. Because the MCU timeline and history is not the same as the comics—and the comic fans have been very accepting of that. This is a new iteration and it may have variations. And I think not being so beholden to everything that had come before gave us some of the freedom to do that.

When you started working on these movies, you had these six Infinity Stones which were the MacGuffins of the entire universe. Did having to incorporate them make your jobs easier or harder? That you had to keep track of where they were, and make sure audiences could understand their purpose without getting too wrapped up in them?

Stephen McFeely: Six MacGuffins is never anyone's first choice, Ben. [Laughs] It's a lot of MacGuffins. We need a MacGuffin, it's fine, we're certainly not adverse to it. It helps in genre storytelling. In the first Captain America, there was going to be the Tesseract or the Cosmic Cube, and I don't think at the time we knew it was an Infinity Stone. I think that was an idea that came later in Phase One. But, we like playing tennis with a net. I don't mind some of the restrictions. I think they allow for innovation and creativity. But yeah, it means you have to check in a lot with other people and make sure about who's using what and when.

The amount of communication behind-the-scenes to keep track of everything must be intense. Are you guys on email threads together, are people texting each other? Or is it just lots of meetings and Skype calls?

Christopher: You know, it is all of the above, and also meeting people on the way to the bathroom at the Marvel office. However you can manage to exchange information. A lot the time, Kevin [Feige, President of Marvel Studios] certainly has probably the widest view of what's going on in each franchise. They have regular meetings of the Marvel brain trust so that they all are on the same page.

We had made two movies with Nate Moore who then went on to produce Black Panther. Panther had barely been written when we started working on [Endgame] and they were shooting while we were shooting, and so we didn't have a very good grasp of how their characters were turning out, and who might work well in these movies. So we kept in regular touch with Nate and kept emailing him and texting him things like, "What's Shuri like? Would she be good in a scene like this? Because we need somebody and we happen to be in Wakanda..." And then he'd tell us. It's kind of done casually but frequently.

When we first met, you mentioned that one of the people who's a little more unheralded but very intrinsic to making this whole thing work is Jon Favreau. Could you explain that a bit?

Stephen: Well I think what we meant was Favreau started it all, he sort of created the tone of the Marvel Cinematic Universe, right? Those first two Iron Man movies... it was him and Kevin and Downey, that sort of triumvirate—and of course the writers—but those first couple of movies set the tone for everything. I don't know if Fav has a ton to do on a day-to-day basis [with the films]... he's listed as executive producer, but we never saw him or anything. He's just more of a grandfather figure. I assume he reads the scripts and he may have given notes to Joe and Ant [Joe & Anthony Russo, directors of Endgame, among other MCU films], but he's too busy to be involved on a day-to-day basis. Oh and remember, he's a great actor!

(Marvel Studios)

Totally. Let's skip ahead to 2015. You've just been signed up to write this two-part Avengers conclusion movie. This is sort of a chicken and the egg question: how much free reign were you given to develop the story and the characters however you wanted? And how much of it were you tied into any sort of preexisting plans or dictates based on the actors' contracts or desire to continue playing these characters?

Christopher: I would say the only dictate was we wanted to make it two movies, and we wanted it to basically be operating around Thanos and the Infinity Stones. They told us, you've got access to everything, go think. And we went off and thought of a million ideas, about sixty pages worth of contradictory ideas. Not all of them were filmable. Some of them involved actors who cost too much. Some of them involved characters they haven't introduced yet. So it was very loose at the beginning, and then as people [at Marvel] developed preferences from what we had handed them, we sort of narrowed the parameters as we went on.

We knew who we had available run of show, as opposed to people who might cost a billion dollars to do a cameo. We gave some thought to that but the story was always paramount and anytime we said, "Boy, we know we shouldn't use this person because they cost too much money." Marvel just said, "We'll get them. Don't worry about it. It's the story."

Stephen: I just opened up the manifesto, and I'm scrolling through it. So I barely heard Chris. I'm fascinated by this document. [Laughs] This is the sixty page document we talked about. I haven't looked at in two years. It's great.

Did you have any sort of thesis statement in that manifesto that tied together what your goals were with the films?

Stephen: Hmm, let's open this up. Let's see. It was really three documents shoved together.

Christopher: I don't think we did. Because we very specifically didn't want to put our thumb on the scale as to which idea we actually wanted to do or not do. We really wanted to sort of blow the menu wide open and let people just kind of think along with us. If we tried to steer it, we would be limiting it to just our imaginations, and there's a lot of people at Marvel who are very good at that sort of thing.

But even back then, were you aware that this was going to be Downey Jr.'s final appearance, all said and done?

Stephen: I don't think they said to us that was definitive. I think when we were brainstorming, we went, "Well alright, certainly a noble death for Tony Stark...if he were to come to the end of his arc, right, if he had gone from selfish to selfless, giving up his life for his fellow Avengers and the universe, that seemed fitting. Could we earn that?" So it clearly was in the air. We knew that part of the mandate of this was to bring the original six Avengers to some kind of closure, and that didn't necessarily mean killing them, but it meant kind of escorting most of them off the stage.

Was Endgame always the title, or was there a title before that was being used?

Stephen: There was no title for a long time, and then it was Endgame...so no, it's not like we switched anything.

There were also rumors that fake scenes were shot to throw off leakers. Was there any validity to that?

Stephen: Not shot, but written.

Christopher: There would basically be variations on what's there, but the ones that sort of killed the secret. For instance, like, if you had the scene where Natasha went off the cliff, it would end with Natasha getting to her knees and walking away. So if anybody read it, they would go, "oh no, she doesn't die." It was that sort of thing. There's a certain waste of man hours if you're actually writing entirely fake scenes. We altered the content of existing scenes to make them less juicy.

In terms of that document mapping out all your ideas for the films—it's awesome that you have it right there with you—what were some favorite or weird ideas that maybe were never going to make it, but you guys really liked or liked thinking about?

Christopher: We gave a lot of thought to, and even wrote some scenes of young Thanos on Titan before whichever disaster befell that planet happened. Just to get a sense of who this person was before he became this intergalactic despot. And they were fun to write, but they weren't necessary. I'm trying to think of other things in that document you have in front of you. A lot of the finished ideas were right there at the start.

Stephen: I'm finding things that I didn't realize that we had back then... Like I have here, it says the "Maltese cube: What if Loki or Thor got off Asgard with the cube?" So, yeah, the stuff that I just sort of completely forgot. Oh, I have here, "Steve Ages: Some dimensional horseplay could result in Steve Rogers aging to his actual hundred year age."

Holy crap, Chris, it says, "Back to the Future: Steve somehow lands in 1945, realizes that he needs an Infinity Stone in order to return to the present. Fortunately, Howard Stark has fished it out of the North Atlantic." [Laughs] So yeah, it really all stems from the manifesto.

Wow. Were there any really dumb ideas that just made you laugh thinking about, that obviously didn't happen?

Christopher: When you're this deep into the science fiction weeds, it's very hard to call any idea dumb. [Laughs] If I was to tell you a story about six stones and a magic glove, you might go, well that's pretty dumb. But it's all about how you go about it. So you just have to leave that part of yourself at the door.

Here's something that I always wondered about: In Thanos' first appearance in The Avengers post-credit scene, there was a mention of him "courting death." In the comics, that's like a big part of his backstory, that he's doing all of this because he's in love with this personification of death. He's got a whole thing for her. And obviously in Thor: Ragnarok, Cate Blanchett plays a sort of take on that character with Hela. Was there any conversation about bringing her into this?

Stephen: There wasn't. I saw that online, that that would be a good idea. And I guess it could be in some other iteration. We didn't even know that she was going to be the villain of Ragnarok. We're starting these films well before that, we're outlining before Taika Waititi had even been hired. So, we came to an early conclusion that some of these celestial type cosmic beings just don't seem to fit at the moment into the MCU's first three phases. They may very well later—you may get the Living Tribunal or Master Order, Lord Chaos or whoever. But it was just too early to do that and we really wanted Thanos to be a sympathetic villain. And if it was all for love, I just don't know if I'd be that sympathetic.

Christopher: Also, for the love of a concept who never speaks to him. It gets just harder and harder to relate.

So you have the document in front of you. Was time travel always on the cards, or were there alternative ideas other than time travel that were considered?

Stephen: Basically, when we decided to kill Thanos and to destroy the stones [at the start of Endgame], we wrote ourselves, or outlined ourselves, into a particular corner. So time travel sort of stems from that. It wasn't necessarily everyone's first idea, but we liked keeping the audience off-balance and that surprise in minute 15 of this film allowed us to do a couple of different things.

Was there any concern that time travel was going to be too confusing for the audiences?

Christopher: I don't know if we were worried about it in the writing in that, people are willing to go down some pretty weird paths a lot of the time. And confusion isn't even always a barrier to enjoyment. In fact, sometimes there is a pleasure to confusion, sometimes. But we did test screen the movie and found that there were people not grasping our version of time travel, and it was causing questions at the end because they were basically relying on Back To The Future for their time travel knowledge. So we had to put in some clarification scene of exactly what we were talking about to differentiate it. so that people wouldn't wonder why Nebula didn't disappear when she shot herself and things like that.

Were you surprised by the controversy, or strong reactions, over Black Widow's fate, and Thor's physical transformation in the film?

Stephen: I'm not following every bit of the controversy. We certainly knew that if you were going to kill the first female superhero of the Marvel Universe, you better have a good reason. And we felt that it marked the end of her journey, that sacrificing herself for the new family she'd discovered and wiping out all the red in her ledger was a pretty satisfying six movie arc. And in terms of heavy Thor—it's a manifestation of his depression. I guess I'm surprised that people are really bothered by it.

Christopher: Yeah, it was never meant to be a gag about weight, it's meant to be... Thor the character who, and also the actor who plays him, are both known for their physical perfection, and you take him down to a very human level where he is wrestling with emotional issues that are very familiar to all of us. It was almost the only place that character hadn't gone yet in the MCU. And so it was really a character choice in terms of: he's been through so much, he cannot remain indestructible. He has to become effectively mortal in order for the character to grow. So that was where it came from.

What about the Lebowski joke? Did you or anyone at Marvel get the Coen brothers' blessing for that?

Stephen: Oh, it's the gag, right? Don't we just say Lebowski once or is it you're talking about: can a person wear a bathrobe and crocs and not call Joel and Ethan?

Yeah, well, that is trademarked by them, I'm pretty sure.

Stephen:[Laughs] Then I have been violating trademark for 10 years. I'm doing it now.

Christopher: You know, he wasn't specifically conceived of as "Lebowski Thor." It was more that when concept art started to come in based on the guidance we were giving them, he began to resemble our old friend The Dude. Just because he was a bit of a schlub on the skids. So it was never like, "we are going to MAKE him Lebowski!"

I was reading some of the other interviews you've done so far, and I'm pretty sure you've already contradicted yourself about the multiverse and whether it does or doesn't exist.

Stephen: We're trying to clean that up in recent interviews, we'll certainly use you as an opportunity.

So let's get into the multiverse: what is the multiverse and does it exist in the MCU? And I need this to be stated once and for all, no take backs.

Stephen:[Laughs] Okay here's what I know. Certainly they bring the multiverse, or the concept, up in Doctor Strange, so it is not new to this movie, if it is in this movie. We actually brought in two quantum physicists, to ask their opinion about time travel and how if it could be real—which we know Ben it is not—how would it work? And both of them said, well, given what we know about particles at the quantum level where new research indicates that the same particle can be in two different places at the same time on the quantum level, that maybe the Quantum Realm established in Ant-Man might allow for some time travel.

And one of these guys is the one that basically said, "listen, I love Back to The Future as much as the next person, but it's probably not how it would work." It's much more likely that if you were to do that kind of stuff, you'd create a branched timeline or a branched reality that you don't just...if you go to the dance with your mom, your brother doesn't disappear. [Laughs]

You can't change what's already happened, that was sort of their big thing. Just on a structural level, you can already imagine if you're in our position, if we're going to go back in time and get six different McGuffins and if every one of those was going to lead to this ripple effect, we would be exponentially screwed. I don't know how we'd even track anything.

So it behooved us to have a system that allowed for things to stay the same in your present reality. And if you go back in time and alter something, one theory is that it creates another timeline. We tried to be very judicious about that. That's what the Ancient One tells Bruce Banner—that generally speaking, it's only the removal of an Infinity Stone that creates a timeline. Again, I don't know if Marvel's going to stick to that or no.

Are you two, at all, involved with the future of the MCU, the next phases and everything? Or do you feel like this is the end of your time with Marvel?

Christopher: It's the end of a chapter for us, one that has been going on for 11 years. We are not currently working with Marvel. There's absolutely nothing to say we won't in the future, but we're not in a room plotting out the next moves. Which I think is healthy, you know? You need to shake things up once in awhile.

You two have been so involved in Cap's story in the MCU from the beginning. If there are stories to tell about his life in the past, or in the multiverse, would you want to be part of writing that? Would that be something you couldn't pass up?

Stephen: That we couldn't resist? I would like to get the phone call...and you're right, I would have a hard time letting someone else do it. So I don't know. Chris and I would have to go to a diner and really decide.

Christopher: Yeah, it's hard to say when you're hanging on because you're greedy and when you're hanging on because you're telling a huge story. It's hard to say what's healthy. This is unprecedented, you know? Someone coming up and saying, "Would you like to write a sixth movie about this character?" That doesn't happen very often.

Very true. Let me ask a big, sort of obvious question that I feel like is the subtext to a lot of these discussions. What is it about comic book movies that have grabbed the zeitgeist so successfully? What is it about them that people can't get enough of?

Stephen: Jeez. It's a modern myth, right? It's shared storytelling. It's the same way Game of Thrones has sort of captured people. Those aren't superheroes, but we're sort of living and dying with every episode. It's so rare that we get a water cooler conversation these days, and it's not really about politics or taking sides, it's about emotional investment.

And obviously the technology caught up to some of Stan Lee and everyone else's imaginations from back in the day, so you could do these things fairly real. Chris, do you have another idea about it?

Christopher: It's wish fulfillment, which is always appealing, particularly when your present might be a little grim or complicated, to step into some place where there is a bit of right and wrong, and a bit of black & white, and someone moral in authority saying, “Don't do that or act like this.” It is refreshing, and I think it's an actual human movie. It's why a lot of these stories were told in the first place. I mean, not just Marvel Comics, but The Odyssey, things like that— put a human through the paces and see what happens so that you can learn from it.

Stephen: Did you just compare yourself to Homer?

Christopher:[Laughs] Only in that I'm blind and not one of you...and I may actually be a concept, not an actual person.

Stephen: Oh, is that right? I guess I haven't done my homework yet.

Christopher: It's a working theory that Homer is basically a catch-all term for several people who went around telling a story.

Stephen: Gotcha.

Christopher: And it's also that there is, I don't know about all superhero movies, but there is just something built into the human psyche that seems to enjoy inter-connected storytelling.

Stephen: Yes!

Christopher: There is a joy that triggers in your brain when you see a character that you know from one place popping up in another, and you go, "Oh, those two strands are connected!" It sounds very simplistic, but it is kind of primal, and I don't quite understand it to tell you the truth.

Stephen: Oh, that actually makes me think. Listen, these things are talked about on the Internet like nothing else, and part of it is because there's expectation by audiences in exactly the way Chris is talking about. Like, "Oh I can't wait until Rocket meets Tony Stark. I've experience them both in different places, and I can imagine what that'll be like." And so, when they only have two lines together, you go, "Oh, I wanted more!" Or, "I wanted different!" So that's partly why sometimes you'll get controversies, you'll get negative feedback. I think more often than not we're getting pretty good feedback and people are happy with the movie, but that's part of it, that emotional investment.

And that also touches on, I think, one of the larger MCU ideas that is kind of exceptional for film. The MCU has brought TV storytelling to the movies at a time when TV storytelling has been thriving, and it has become a style audiences really respond to.

Christopher: Yeah, it's a rare thing for a franchise to be going so long that you can attempt something not unlike a TV show. We were figuring out the other day that just in Captain America alone, if you count the movies we worked on, that's about the run of a season of TV timewise. Serialized storytelling's not new, but we now have the resources to really put it on in a way that honors the material. It's a rare opportunity.

You mentioned before about fans and feedback, and how Endgame has gotten a pretty amazing reception and very good reviews. I think it's safe to say people are more or less incredibly satisfied with the journey, and that there was just this real culmination that happened in the movie. But, to play devil's advocate here for one second...as you said before, Tony Stark's storyline over the course of these 11 years is that he goes from selfish to selfless. But, I have a friend who has been bugging me for weeks about this arguing, "Isn't it selfish to put one life above millions of people whose lives were disrupted and traumatized by the snap and the five year gap?"

Stephen: Alright, which life is your "friend," code for Ben, referring to? [Laughs]

Christopher: He's talking about his daughter.

Stephen: He's talking about Tony's daughter? Ah! So your "friend" would argue that the selfless choice would be to allow his daughter to die and to reverse five years completely and reset it? Tell your "friend" that I can't imagine that anyone loves him. [Laughs]

Christopher: Tell your friend he's second only to Thanos. [Laughs] No I mean, one, Tony initially says he's not gonna go along with it for that very reason but then does go along with it. And while he's hoping to not affect his family, he doesn't know for sure that that's gonna happen; and he does wind up losing his family, but he doesn't lose them, they lose him. So he does sacrifice everything. But I also think too much has happened to the existing creatures of this universe. You can't erase five years of experience. New things have happened.

Stephen: That was really important. It was really important to us to own the snap. I think it would be really cheap storytelling if you just erased it all. So that was one of our mandates, was to treat this all real seriously. And then when "five years later" comes up, that's serious. That's going forward, and it's gonna complicate all the Marvel movies hence.

Christopher: Yeah, and that relates to why the MCU has stayed vital. It goes for big swings, it makes big changes, and it owns them. If we went back in time five years and erased Thanos and the end of Infinity War never happened, there'd be no reason to make these movies. It would have come back to the exact spot where it started and it wouldn't have progressed the universe.

Stephen: And we would be getting crucified. [Laughs]

I know you don't believe me that I have a friend asking about this, but I do think that makes sense, and it's much more interesting storywise that way. My last question: now that Cap is retired, or he's an old man or whatever...who has the best butt in the MCU now?

Stephen: Ahhh! I can't believe you didn't lead with this. Jeez, who's got the best butt?

Christopher: I'm gonna go with Groot.

Stephen: Oh yeah, pretty good, yeah. Can I say Rocket? Is that gross? [Laughs]

It's all on the table.

Stephen: Exactly right. I'm not judging anybody.