For a good few years at this point, the road map for the Marvel Cinematic Universe has been clear to anybody paying attention. Since the central MacGuffin of Captain America: The First Avenger and the appearance of a certain purple, craggy-faced cosmic villain in the post-credits sequence to The Avengers, it's been obvious that the interlinked superhero franchises have been building up to adapting one of the classic, crazy crossover storylines from the comic books: The Infinity Gauntlet. Everybody knows about that, right? Which is what made this morning's bombshell all the more surprising. Marvel totally tricked us. Or, at least, they did a sort of double-bluff with audiences - if Guardians Of The Galaxy is anything to go by, The Infinity Gauntlet is definitely coming at some point. But before that they're apparently going to be adapting another huge crossover event to the big screen, in the form of Civil War. Reports started trickling in earlier today that Robert Downey Jr had signed on to play Iron Man in Captain America 3, and that film's plot would launch "elements" of the Civil War story. What exactly is that story, though? Well, if it's anything like the comics, it'll tear the MCU apart. Former friends fighting each other, bad guys and good teaming up, and a possible return by a certain wall crawler. Here are ten things you need to know about Marvel Civil War. Spoilers for the Civil War comics and quite possibly the future of the Marvel Cinematic Universe ahead...