While Robert Downey Jr. will have a substantial role in Captain America: Civil War, he wants Marvel fans to know full-well before they head into theaters that they are not getting Iron Man 4. This is definitely Steve Rogers' story, and Chris Evans is the lead in a movie that will bring more Marvel characters to the screen than ever before it.

In an interview with Empire, Robert Downey Jr. offered new details about the storyline of Captain America: Civil War. Based on the comic book series of the same name, the plot follows Captain America and Iron Man as they stand on opposing sides of the Government's newly instated Hero Registration Act. While Steve Rogers is against it, Tony Stark thinks that it's a very good idea. But don't consider the multibillionaire the villain just yet. Robert Downey Jr. explains:

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"The main thing to me is, and this is where I think the Russos are quite brilliant and where Kevin backed the play, is what sort of incident could occur and what sort of framework could we find Tony in? The clues are in Avengers: Age of Ultron, about where we might find (Tony) next. But what would it take for Tony to completely turn around everything he's stood for, quote-unquote, because he was the right-wing guy who could still do his own thing....There's always the bigger overarching question, that Joss brings up all the time - it's kind of weird that these guys would have all these throw downs all over planet Earth and it looked like a little collateral damage happened over there, and yet when the movie's over, it's like nobody minds. You have to figure, 'Were you to ask the question, what would the American government do if this were real? Wouldn't it be interesting to see Tony doing something you wouldn't imagine?'

While that certainly sounds like Tony Stark will have a huge character arc in the movie storyline for Captain America: Civil War, Robert Downey Jr. doesn't think fans should consider it the next chapter in the Iron Man franchise:

"Ultimately it's Steve's story; it doesn't say 'Iron Man 4: Civil War'. I think that's great too. I think Chris [Evans] has been hungry to bring even more of an underside and some shadow to that. I remember the comics - on the surface you got the sense that Cap was baseball and apple pie, but underneath there was all this churning stuff of being a man out of time. Now we know he's made his peace with that. What's the bigger issue? It can have a little something to do with the past, but it can be about someone becoming more modernized in their own conflict."

Though Captain America: Civil War sounds like it is Steve Rogers story at it's core, it promises to be the biggest Marvel movie yet, as it will feature new and old members of the Avengers while introducing Chadwick Boseman as Black Panther and a new Spider-Man. We may even get our first glimpse at Benedict Cumberbatch as Doctor Strange. Shooting is set to start this spring, with Captain America: The Winter Soldier directors The Russo Brothers returning to direct.