6. Hawkeye's Family Are Murdered
At the end of Avengers: Age Of Ultron, it appeared as if Hawkeye had decided to retire from the superhero game to finally be with his family. What then could convince him to get involved with the conflict in Captain America: Civil War? As dark as this would be for a Marvel Studios movie, the death of his wife and children certainly fit the bill, and as there's precedent in the comic books for that, it could very well happen. While it's been made clear that this movie has nothing to do with secret identities, if Hawkeye registers with the government, the family that Nick Fury kept secret for him obviously risk being exposed. Assuming for a second that someone like Baron Zemo is going to be involved with the Accords - the movie's official synopsis definitely appeared to indicate that there's someone pulling the strings behind the scenes - then Hawkeye's loved ones coming under fire does make sense, and there are even rumours suggesting that Crossbones will be responsible for this massacre! Killing off Hawkeye's family may seem unnecessarily harsh, but it would give Jeremy Renner some really strong material to work with and explains why Clint Barton is fighting against his longtime ally, Black Widow.