The reveal of the new Avengers lineup at the end of 2015's "Avengers: Age of Ultron" took many moviegoers by surprise -- including one of the new Avengers. During IGN's set visit to "Captain America: Civil War," Anthony Mackie revealed that he didn't know that Falcon joined the Avengers until he saw the film at "Age of Ultron's" premiere.

"It's weird. You never know. They never send you the whole script. Like when they asked me to do ['Age of Ultron'], they sent me two scenes," said Mackie. "There are two hours and seven minutes around those two scenes, but I never got to read it. When we were at the premiere I was like 'Cool.' I'm with my son and he gets to see his daddy in two scenes in 'The Avengers.' By the end of the movie I turn around and they're like 'Avengers Assemble!' I'm like, 'Holy s**t! I'm an Avenger!!' So I turn around to everybody with me and they were like, 'Dude! You're a f**kin' Avenger!' 'This is f**kin' amazing."' So, that's the story of my Marvel life."

The scene, which saw Mackie's Falcon, Vision (Paul Bettany), Scarlet Witch (Elizabeth Olsen) and War Machine (Don Cheadle) assemble for the first time in the Avengers' new compound, was shot without the context being known. "I had no idea. I flew in, Chris [Evans] and Scarlett [Johansson] are up top and the rest of us are standing there. It was like 'Cut. Anthony fly in. Action. Hm-hm-hm. Cut. Alright, thanks!' That was pretty much it. Six months later you go to a premiere and you s**t yourself."

Mackie also talked a bit about how he relates to his teammates and the other heroes in "Civil War," saying that he acts as more of an audience surrogate.

"I'm more the audience's perspective, so when Scarlet Witch is all [waves hands], I'm like, 'You saw that? Right. Just making sure you f**kin' saw that.' Scarlet Witch and her crazy rave baby technique and Ant-Man and him riding an ant. Alright, cool! That's what he does, he shrinks and rides ants."

Directed by Joe Russo and Anthony Russo and starring Chris Evans, Robert Downey Jr., Scarlett Johansson, Elizabeth Olsen, Sebastian Stan, Anthony Mackie, Paul Rudd, Chadwick Boseman, Don Cheadle and more, "Captain America: Civil War" opens May 6, 2016.