The actress opened up to Jimmy Fallon about all the hoops Marvel made her jump through to prevent spoilers.
The release of Avengers: Endgame is just days away, and as fans have been excitedly waiting to see the long-awaited super hero saga hit the big screen, Marvel has been doing everything they can to curb possible spoilers.
As it turns out, the level of secrecy was just as intense on set for the actors, even as they were filming scenes for the movie.
Brie Larson, who starred as the eponymous cosmic super hero in Captain Marvel, sat down with Jimmy Fallon on Wednesday's Tonight Show and she recalled one example of just how tight the filmmakers were holding the lid on the movie's major plot points.
"We filmed Endgame before Captain Marvel. We didn't even have a script yet for Captain Marvel," Larson recalled. "I flew to Atlanta to start shooting, I had no idea what I was doing, and I arrived and they gave me a piece of paper that was a full page of dialogue and action, but all of it was redacted except for my one line."
The actress explained that she then went to hair and make-up to get ready for her scene, and when she asked who else was on set that day, all the make-up crew pretended not to know.
"I was like, 'Really?! They're not allowed to tell me either?'" Larson said, explaining how it had suddenly dawned on her how different shooting a big budget blockbuster was from any other kind of filmmaking. "It wasn't until I walked on set that I was like, 'Oh, crap. I'm, like, in a Marvel movie right now.' And then I couldn't talk about it."
Even when it came to filming a post-credits tag for her own film, Captain Marvel, the process was still shrouded in mystery and secrecy.
"There's a tag in Captain Marvel where it like whip-pans over to me and I go, 'Where's Fury?' But I didn't know that was a tag for Captain Marvel," she recalled. "I didn't know what that was, and there was also nobody else there. I was by myself on a green screen."
"I walked in and they were like, 'Just real quick, we're just gonna whip-pan over to you and you're gonna go 'Where's Fury?'' and I was like, 'Cool, cool, got it,'" she said. "So they whip-pan over to me and I go, 'Wait, so, like, but where is he, actually? Like, is he in the room? What room am I in? Is he in the other room? Or is it like another universe?"
"They were like, 'He's very gone.' And I was like, 'I think this means he's, like, he's dead,'" Larson added.
In the completed scene, Larson appears out of nowhere in the midst of Black Widow (Scarlett Johansson), Captain America (Chris Evans), War Machine (Don Cheadle), and Bruce Banner (Mark Ruffalo). However, on the day of the shoot, they couldn't even tell her that much.
"I was like, 'OK, who else is in the room?' And they were like, 'Five people,'" Larson recalled with a laugh, adding that they used tape marks on the walls to stand in for her eventual co-stars.
"Then, I had the pleasure at the Captain Marvel premiere of seeing what the scene was and going, 'Oh! That's what that meant," Larson added.
Avengers: Endgame, the final chapter in the Avengers saga, hits theaters April 26.