Marvel's Cinematic Universe makes it possible for superheroes to come and go with cameos all around. That's what happened at "Ant-Man" (spoilers ahead though) where Scott Lang as Ant-Man was called in to help the Winter Soldier.
In the post-credits scene of "Ant-Man," a preview to "Captain America: Civil War" was revealed. The scene depicted Falcon who had a run in with Ant-Man in the early parts of the film brought Steve Rogers aka Captain America to an unknown location where Bucky Barnes aka Winter Soldier was evidently trapped. It was not revealed how he got held up in that location but it was an emergency that warranted Ant-Man's help.
Sebastian Stan, who plays Bucky in "Captain America: Civil War," gave out details and explanations as to how his character found himself in that predicament.
According to Cinema Blend, Stan hinted in an interview with Buzzfeed that Bucky's ensnarement was made possible because of a villainous individual rather than by doing it himself. The actor said, "I think [what Bucky was caught in was] more of a vise. But it would never happen at his own hand, by his own doing."
He also cautioned viewers who gave their own interpretation with what they saw in the ending credits that "whatever you're seeing on the surface, it's not as obvious as that."
As to his state of mind, Bucky apparently blocked out HYDRA's brainwashing when he rescued Captain America's life in "Captain America: The Winter Soldier." However, he's still not totally in control of himself, as evidenced by his expression when he gazed at the memorial in honor of him at Captain America's exhibit at the Smithsonian.
In "Avengers: Age of Ultron," Captain America and Falcon were still searching for him, in between that time and "Ant-Man," the duo gather evidence which led them to his present situation. As to who was responsible for his arm being trapped in "Captain America: Civil War," it's a toss between Baron Zemo and Crossbones, primarily because he plays a role in the plot to end Captain America's life.
Meanwhile, Comic Book reported that "Captain America: Civil War" will see a division between Iron Man and the Captain himself, which will leave the Avengers in chaos.
Other Avengers will have to take sides between Captain America or Iron Man. Recently, as per Movie Pilot, actor Jeremy Renner who plays Hawkeye was seen on the set of "Captain America: Civil War" wearing a cap that reads "Team Captain America." This led fans of the superhero flick to believe that maybe Hawkeye aka Clint Barton will indeed be on Steve Rogers' side or he may be just wearing it to throw everyone off on where his loyalties really lie.
Well, Hawkeye will have only four options, team Captain America, team Iron Man, be on both teams or no team at all. Anywhere he went with his decision, viewers and fans alike will have to wait for the movie's release.
"Captain America: Civil War" hits theaters May 6, 2016 and is directed by Joe and Anthony Russo.