If there’s one thing that the recent trailer for Captain America: Civil War made clear, it’s that Bucky Barnes, a.k.a. Winter Soldier, is going to have a central part in the movie. With Iron Man on one side trying to bring him in for the events of Captain America: Winter Soldier and his old friend Steve Rogers on the other side trying to defend him, the remainder of the MCU is forced to decide where their alliances lay.

Whereas the Civil War of the comic books was sparked by a fight between the New Warriors and the villain Nitro, which resulted in the deaths of hundreds of civilians, the film version makes it a bit more personal for the heroes on both sides by making Winter Soldier the catalyst instead. While it makes sense to shift the focus to avoid having to introduce new characters with whom audiences are unfamiliar, there’s still some explaining to do as far as just who Winter Soldier is.

In addition to presenting some back story for Winter Soldier, Civil War pushes his narrative forward. Actor Sebastian Stan spoke to EW about his character’s journey:

Stan also spoke about how his relationship with Bucky Barnes changes Captain America and makes him question his status of poster boy for the American government:

“This movie certainly deals with what’s happened to him. I mean, what have we gotten as a result of Bucky and the Winter Soldier? You know, here’s the guy when you merge the two. This is what came out. To me, he’s never really going to be Bucky Barnes again. There’s going be recognizable things about him, but his path through the [experiences of] Winter Soldier is always going be there, haunting him. He recognizes his past, but at the same time he’s sort of a new character, too.”

“We get to see another side of him. I mean you’d wonder, right? After so many years of being loyal and morally impenetrable and always doing the right thing that he wouldn’t somehow at some point go, ‘Man, like, what am I fighting for? What’s my life? What am I living for?’ I think this movie very much tackles those questions for Steve Rogers. He’s been questioning things I think for a long time and this is where he’s deciding to follow his instincts and not what people tell him is right or wrong.”

Steve and Bucky’s friendship is strong enough that, even after 70 years, Steve is still prepared to side with his childhood pal against some of the strongest superheroes around. More importantly, he’s also willing to fight those whom he would consider friends, and who fought alongside him in the battle of New York, in order to protect Bucky. There’s a lot hanging in the balance here.

In the end, the outcome of Captain America: Civil War will affect the future of the entire MCU. Friendships will be shattered, loyalties will be tested, and new alliances will be formed. As for what happens to Steve Rogers and his friend-turned-enemy-turned-friend-again Bucky Barnes, audiences will be finding out next May.

Captain America: Civil War will release on May 6, 2016, followed by Doctor Strange – November 4, 2016; Guardians of the Galaxy 2 – May 5, 2017; Spider-Man – July 28, 2017; Thor: Ragnarok – November 3, 2017; Black Panther – February 16, 2018; The Avengers: Infinity War Part 1 – May 4, 2018; Ant-Man and the Wasp – July 6, 2018; Captain Marvel – March 8, 2019; The Avengers: Infinity War Part 2 – May 3, 2019; Inhumans – July 12, 2019; and as-yet untitled Marvel movies on May 1, July 10 and November 6, 2020.

Source: EW via CBM