Marvel went through great lengths to keep the plot to Avengers: Infinity War and Avenger 4 a secret from everyone, including the actors on set. The actors only got scripts for the scenes that they were a part of, and a general overview of what’s happening in the story and their character’s motivation at the time of the scene from the Anthony and Joe Russo. That’s is about it.
Is this a wise practice? According to Don Cheadle, who plays James Rhodes a.k.a. War Machine in the MCU, he is actually happy not to know anything about the plot:
“It’s very interesting on set, obviously, when you don’t know the entirety of everything and things are changing [in] real-time. It keeps you on your toes, that’s for sure. But it’s ultimately exciting and it’s as fun for us sometimes discovering it as it is for the audience. ‘Cause we’re like,‘Oh we had no idea how that was gonna turn.’”
“The story is really intricate. It has a little bit of a different feel than the last movies have. There’s a little more gravitas, and it kind of has to be that way. … I think you have to try to bring in some more serious elements. And I think Rhodey being injured was a part of it, kind of starting the ‘Oh, wait, people can really get hurt. Things can really go south for these characters.’”
Cheadle is referring to his big moment in Marvel’s Captain America: Civil War, when War Machine is hit by an accidental blast from the Vision. His character crashes to the ground, paralyzing him. By the end of the film, Rhodey is equipped with high-tech braces from Tony Stark.
According to Cheadle, he doesn’t know if his character will survive the events of Marvel’s Avengers 4, but his characters reaction to meeting the cosmic universe is priceless:
“When we start leaving the planet and talking about things coming from outer space, [I’m] like, ‘Dude, I don’t even know, what is that?’ I know how to fight guys and in tanks and weapons and that. [This is] beyond my pay grade.”