Captain America: Civil War has an enormous twist late in the movie that Mike Ryan explored in-depth with the screenwriting team. It changes the whole tenor of the movie, and it seemingly comes out of nowhere. But sharp-eyed viewers might have figured it out right when they saw the opening scene.
If you don’t want spoilers, go forth with this GIF. Poor Bucky.
No, seriously, I’m about to ruin the movie for you.
Captain America: Civil War opens with Bucky taking out a car in the American backwoods in 1991, and stealing a batch of super-soldier serum from the trunk. It’s seemingly plot relevant because of the imminent threat of a squad of unstable assassins, sitting in the deep freeze of Siberia. Surely Helmut Zemo will unleash them upon the world! It turns out, though, he doesn’t. Instead, he wants to show Tony video evidence of the crash, and we see Bucky kill Tony Stark’s parents. Tony, as you might have guessed, does not take this very well.
It turns out, though, that Captain America: Winter Soldier set this up, albeit in a misleading way. During Cap’s confrontation with what’s left of Arnim Zola, Zola reveals that Howard Stark was killed. If you look closely, you can see the date is…1991. However, to throw you off the scent a bit, they use a photo of Dominic Cooper, who plays young Howard, instead of John Slattery, who plays the older Stark. See for yourself:
The fact that Bucky committed the assassination is the missing piece of information, but it’s enough. Considering how the movie ends it, we won’t be surprised if the next Avengers movie features a very angry Tony with a very large suit of armor declaring it Bucky season.