Rumors of Iron Man 4 have been going back and forth, and lately there have been some theories on what kind of plot could take place.

Avengers 2 Character To Replace Tony Stark?

On Thursday, Movie Pilot brought up some possibilities on what kind of story could take place in Iron Man 4, assuming the film actually gets made. One possibility is that the superhero could be headed to space if Guardians of the Galaxy does well. According to the site, there have been rumors that Iron Man could make a cameo appearance in Guardians. And if the film that is set to hit theaters in August does well, then there could be a collision between Tony Stark and the guardians.

The site also brought up a potential storyline of showing Tony Stark's teenage self if Robert Downey, Jr. doesn't decide to reprise his character. There is a high possibility that this could happen after an interview with The Edge that teased the chance that someone younger could take over.

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"The smart money is you have to look at everybody's age," the actor said. "I'll put myself at the top of the list. Sooner or later, they've got to start over and get somebody young. I'm not there with them yet."

Downey, Jr. gave some more scoop on the idea of finding a different actor. According to him, it would relate better to younger audiences to have someone who's not the actor's age.

"When you really think about it at the end of the day, these films are entertainment largely driven by young folks," the actor said. "There is something very honorable about that."