Captain America: Civil War wasn’t always going to be the third Captain America film – that was a result of WB announcing Batman v. Superman: Dawn of Justice.

No, the original Captain America 3 would have been based on the Madbomb storyline from Captain America #193-200 by Jack Kirby. This was revealed by Joe and Anthony Russo who also explained the film would not have had an appearance from Robert Downey Jr.’s Iron Man.

There was a period where we did discuss a third act that revolved around the Madbomb from Cap mythology,” Anthony Russo told EW. “It didn’t have anything to do with Civil War, and if we couldn’t get Downey – in the very, very early conversations before we nailed him – somebody pitched the idea of a third-act that revolved around the Madbomb, which makes people crazy. It almost like zombifies them – but not literally.”

Anthony Russo went on to explain that,

The charm of the Madbomb is that you turn hordes of people into berserkers. That was the physical challenge that Cap and company would have had to face. The notion of the Madbomb would have been Cap having to fight civilians and how he would he handle that,” Joe Russo said. “We were always trying to put him into these interesting moral conundrums because of his nature. That would have made a compelling third act because if civilians are the antagonists, how could he stop them without killing them?”

“Somebody you know has turned into a zombie and now you have to fight them,” Anthony said. “And there would have been the emotional component of that.”

Personally, I think that would’ve been an interesting concept. And I can’t help but be reminded of the “Marvel Zombies” storyline – too bad that’ll likely never be adapted, though. Maybe we’ll see the Madbomb concept revived in someway, and in that way not only will we have our “true” Captain America 3, but we might also have the best we’ll ever get regarding a “Marvel Zombies” adaptation.

Source: EW