Lupita Nyong'o was in talks for Marvel's Black Panther back in May, but the studio made it official at San Diego Comic-Con this weekend. While she was speaking to Marvel themselves, she let slip a few plot details she's probably going to get scolded for later.

Nyong'o was one of Marvel's big Hall H announcements along with Guardians of the Galaxy Vol. 2 details, Brie Larson being named as Captain Marvel, and adding The Walking Dead's Danai Gurira to Black Panther's already amazing cast.

What we already knew about the film was this: Creed's Ryan Coogler is directing, Chadwick Boseman is starring, and (revealed at the convention) Michael B. Jordan's character is playing villain Erik Killmonger. Besides it taking place in the fictional African nation Wakanda, Marvel has been pretty tight-lipped on story details. That's why it's kind of funny Nyong'o spilled some secrets on Marvel's own livestream.

"I feel so privileged to be a part of these really, really iconic universes," she said, including her other big franchise, Star Wars, in the mix. "The enthusiasm from the fans and stuff, you know the followers, the faithful followers is really encouraging."

Since she hasn't started filming yet, the actor said she isn't quite sure what's in store for her but did give a very tiny bit of intriguing info.

"Well I can say a little actually. I can say more than I could about Star Wars," she said. "I play Nakia, who is member of the Dora Milaje which is, as I'm sure you know, a special forces group from Wakanda. And the story of this Black Panther is...what I am allowed to say? The story is that the Black Panther's leadership is been threatened by two foes that come together, and so Black Panther gets the help of the C.I.A. and the Dora Milaje to try and defeat the enemy."

"Someone's going to fire me shortly," she added, "I have to shut up now."

Here's the video if you'd like to watch for yourself.

At 1:54:37, Gurira comes on to talk a little bit about comic book fans and then 1:56:13 Nyong'o steps in.

Jill Pantozzi is a pop culture writer and host who reports on all things nerdy and beyond! Her blog was recently relaunched with Patreon support and she’s formerly Editor in Chief of The Mary Sue. She’s written for MTV, Tor, Playboy, Publishers Weekly, IGN & more. You can keep up with Jill, and her cats, on Twitter at @JillPantozzi.