(Major spoilers ahead for 'Civil War.' If you're still reading, I'll assume you've seen it and want to dive headfirst into a reasonably insane fan theory.)
Bucky Barnes's past comes back to haunt him in a big way in [Captain America: Civil War](tag:994409) when Baron Zemo successfully reactivates the brainwashed Winter Soldier with the help of the notebook containing his 10 trigger words.
The movie's opening scene, a flashback to 1991, finds the Winter Soldier on a mission to apprehend and kill Howard Stark and acquire the serum contained in the trunk of Stark's car. In the process, he also strangles Maria Stark to death, before shooting out the security camera that captured the brutal act.
The fact that the security cam being located where it was is a huge coincidence has not gone unnoticed, but a new fan theory suggests that the camera may have a bigger role to play in a conspiracy involving HYDRA and Tony's mother.
The theory, in essence, is this: Maria Stark is working with HYDRA. She helps to orchestrate the death of her husband that night, and the Winter Soldier in turn fakes her death — which, perhaps crucially, is not actually seen. We only see Bucky's hand wrap around Maria's throat before the camera pans out of the vehicle.
Initially, I questioned why he wouldn't shoot out the camera beforehand — he clearly knew it was there — but, viewed in the context of this theory, the sequence makes a lot more sense. If he deliberately shoots the camera out afterwards to create the illusion that Tony's mother has been killed, Maria can then be taken out of the field without looking for her or asking questions.
The killer clue? Upon reactivation, Bucky is given orders to "acquire and extract." The acquire part clearly refers to the serum that he takes from the trunk, but what about the extraction? The command could be read as an instruction to "acquire the serum, extract our agent."
There may be another hint buried early in Civil War. In the "altered" memory of his final encounter with his parents that Tony screens to an audience at MIT, Maria encourages her son to say goodbye to his father. Although on Tony's part in this is merely an acknowledgment of his regret at his fractured relationship with Howard, it could also be intended as a clue from the Russos to the audience that Maria knew of her husband's impending fate.
Like most fan theories, there are a couple of holes in logic; for instance, whose body was switched with Maria's in the car if she wasn't actually killed? It would take some pretty intense plastic and dental surgery to make that convincing. The question of why Maria would double-cross the son she presumably loved also remains to be answered, unless she'd been with HYDRA Tony's entire lifetime.
On balance, though, I'd have to say this is a pretty strong theory. More than that, it also has the potential to set Tony Stark on an entirely new arc within the MCU, beginning with the most personal Iron Man movie ever if Iron Man 4 should go ahead. Credit for the initial theory goes to the Movie Pilot creator Kevin Gay.
Relive Cap and Bucky going at it in this thrilling sequence from Civil War, and tell me: