Warning: The following piece contains major spoilers about "Captain America: The Winter Soldier."
Marvel Studios might produce blockbusters with an efficiency similar to how Chipotle makes burritos, but don't try to accuse the comics empire of playing things safe. Since "Iron Man 3" kicked off Phase 2 of Marvel's Cinematic Universe, the studio has thrown caution to the wind with increasing regularity, both with plot twists (the identity of Mandarin in "Iron Man 3"; Loki's bait and switch in "Thor: The Dark World") and projects (the forthcoming "Guardians of the Galaxy").
Thus far, however, nothing compares to what happens in "Captain America: The Winter Soldier," the movie equivalent of 52 Pickup. There's so much crazy stuff in "The Winter Soldier" that not only does the film serve as a sequel to "Captain America: The First Avenger," but it feels like a prequel to "Marvel's The Avengers: Age of Ultron" (not to mention a game changer for whatever is happening on the ABC series "Marvel's Agents of S.H.I.E.L.D.").
Before the release of "The Winter Soldier," HuffPost Entertainment spoke to screenwriters Christopher Markus and Stephen McFeely (the pair also wrote "Captain America: The First Avenger" and "Thor: The Dark World") about the most shocking parts of their "Captain America" sequel.
They Blew Up S.H.I.E.L.D. ...
As audiences might have noticed, "Captain America: The Winter Soldier" takes S.H.I.E.L.D. (Strategic Homeland Intervention, Enforcement and Logistics Division) and blows it up.
"There are some big things that we come up with, but [Marvel Studios head] Kevin Feige is the one who walked in and said, 'We are prepared to destroy S.H.I.E.L.D.,'" McFeely said. "You say that and it opens a gigantic shaft for your plot to travel down. You're not going to destroy S.H.I.E.L.D. by having a giant bad guy come in and knock it over. It almost dictates a conspiracy story. That was when things really took off."
For the writers, that meant HYDRA, the evil Nazi organization that Captain America (Chris Evans) fought in "The First Avenger." In "The Winter Soldier," it's revealed that HYDRA has been secretly in control of S.H.I.E.L.D. and was part of the reason the organization existed in the first place. By the end of the film, the conspiracy is uncovered and the organization's headquarters are destroyed, leaving both the villains and heroes splintered off in different directions.
"One of the nice things about tearing down S.H.I.E.L.D. is that eventually it will require the Avengers to fill the hole," Markus said about how the reveal will fold into future Marvel movies. "If you've taken out the world's police, somebody has to do their job."
... But They Never Called In The Other Avengers
While The Avengers might put S.H.I.E.L.D. back together again in some subsequent Marvel movies, the group is noticeably absent throughout "The Winter Soldier," save for Captain America himself and Natasha "Black Widow" Romanoff (Scarlett Johansson), his partner throughout the film's story. (Tony Stark is mentioned in "Captain America: The Winter Soldier," but never called in as backup.)
"It doesn't really happen in the comic books. If I'm reading a Cap story, I'm not worried that a problem doesn't get solved because they didn't call Asgard. We have to assume that the similar rules are operating here," McFeely said about the lack of support from Captain America's super friends. "In this particular case, we were really trying to do some version of 'Three Days of a Condor.' It's like, 'I don't know who to trust or call. This story doesn't get expanded by calling in reinforcements. I have to hunker down and solve it myself.'"
As Markus noted as well, a key twist in "The Winter Soldier" involves Nick Fury (Samuel L. Jackson) dying in front of Captain America (it's later revealed that Fury faked his own death to help uncover the conspiracy).
"A man who got shot, quote-unquote, to death in front of him told him not to trust anybody," Markus said. "It's either I trust people and get them killed or I don't trust anybody. It was a pretty easy call not to really bring anybody in. Plus, we have Natasha. Thor's in Asgard, you can't call him. I don't think you can call the Hulk, I don't think he has a phone. You just have to worry about Tony and if he's on a yacht somewhere ..."
They Kept The Winter Soldier Alive For Future Movies ...
Beyond all those S.H.I.E.L.D. shenanigans, "Captain America: The Winter Soldier" also finds time to introduce The Winter Soldier (Sebastian Stan), a HYDRA assassin who is actually Captain America's former BFF, Bucky Barnes. Winter Soldier survives the third-act battle royale with Captain America, and, in the film's final scene -- after the credits -- is shown investigating his true origins.
"Winter Soldier is, even to this day in the comics, an unfinished story," Markus said. "You can't kill people for 70 years and get fixed. You can only make incremental little steps toward some kind of attempt at redemption. Not even guaranteed redemption. We cracked him in the last battle, but we wanted to leave it ambiguous. So there were people out there thinking he's either a stone cold killer or that everything is fine."
Expect the next "Captain America" film, set for release on May 6, 2016, to tackle that fallout. According to McFeely, the writers are "trying to pull at that thread" for "Captain America 3."
... And They Brought Back Arnim Zola ...
Perhaps the craziest scene in "Captain America: The Winter Soldier" is when Captain America and Black Widow stumble onto HYDRA scientist Arnim Zola (Toby Jones), whose brain is living inside a computer at the original S.H.I.E.L.D. headquarters, which is located underneath an Army barracks in New Jersey.
"It was hard," McFeely said of the sequence, which provides Captain America (and the audience) with a ton of key details regarding the history between HYDRA and S.H.I.E.L.D. "We needed the exposition of, 'Here's what's really going on,' but we didn't want him to go into a file room and read files and get on a computer. We always liked the idea, even though it was a little sci-fi and comic book-y, of Zola continuing to live in different forms. We went through a lot of fights and a lot of, 'Are we really going to do this?' Even toward the end, the biggest problem was how do we make sure he tells all this information without just monologuing. Why is he telling Cap this? The idea that he's trapping him sort of works, hopefully, and gives Cap the chance to withstand this big bomb and save Natasha. It all dovetails nicely, but it was a pretty heavy lift."
... But They Never Consider Resurrecting Red Skull
One of the biggest rumors circulating the Internet before the release of "Captain America: The Winter Soldier" was that Robert Redford had actually been cast as Red Skull in the film. Instead, Redford stars as Alexander Pierce, a top S.H.I.E.L.D. executive who is uncovered as a key villain during the film's second act. (His skull is not red.)
"Put yourself in our spot. It's 2011, the movie hasn't even come out yet. We're trying to figure out what the second one is, and our first idea is going to be, 'Let's bring back the exact same villain'?' McFeely said about the rumors. "We've got to work harder than that."
As Markus noted, having Red Skull revealed as the ultimate villain also didn't fit the storyline.
"If we're trying to tell you that the modern day has gotten murky and the good guys are sometimes indistinguishable from the bad guys, if your bad guy has a giant red skull for a head, he's not indistinguishable," Markus joked. "He's your bad guy. We wanted to say S.H.I.E.L.D. was corrupted from within."
Best Of All, They're Fine With Leaving Things Off On A Cliffhanger
"Captain America: The Winter Soldier" ends on a note that recalls "Star Wars: Episode VI - Empire Strikes Back," as all of the film's key characters are left without total resolution.
"We needed to wrap enough people up -- or just tell you where people are going to be, possibly, in 'Avengers 2' or 'Captain America 3,'" McFeely said of the denouement, which was also done out of necessity because of what came before.
"We also dropped such a bomb on everybody by tearing down S.H.I.E.L.D., we needed an aftermath," Markus said. "You couldn't just say, 'Oh, this building fell down! Fade to black.' It's also just fun to leave people not in a completely stable place. If you're dealing with a movie about the real world, the real world never gets fixed. The real world gets adjusted and maybe you fix one problem and another leak springs up. That's why you're only president for eight years because your heart can't take it."
"Captain America: The Winter Soldier" is out now; Captain America will return in "Marvel's The Avengers: Age of Ultron."