Can 'Captain America 2' Cast Keep a Secret?

Captain America: The Winter Soldier ironically doesn't come out until next spring, but that's not keeping the supporting cast of the film from opening up about it and sharing a laugh in the process. We caught up with The Winter Soldier co-stars Anthony Mackie, Samuel L. Jackson, Emily VanCamp and Frank Grillo at Comic-Con in San Diego for the scoop – and to see how much new information could be divulged without the specter of the Marvel machine breathing down their backs!

Related Video: VanCamp on 'Amazing' Captain America Experience

"It's different," says Sam about the new movie, joking, "That's the only thing I can say without my head exploding. I feel my phone vibrating now – you've said too much. Chill."

"They said you can never say anything about anything," agrees Frank. "It's scary. I'm even afraid to talk to my sons. They hate me."

Picking up where Marvel’s The Avengers left off, Chris Evans is back as Steve Rogers/Captain America, the former World War II super soldier (who was frozen in suspended animation) who is now struggling to fit in the modern world. In the new movie, he teams up with S.H.I.E.L.D. agent Black Widow/Natasha Romanoff (Scarlett Johansson) to battle a powerful yet shadowy enemy in present-day Washington, D.C. – the return of his former best friend, Bucky Barnes (Sebastian Stan).

"They kind of wanted to mirror sort of a '70s political thriller a little bit, which I think is a really interesting way to tell this story," says Emily.

In theaters April 4, 2014, Captain America: The Winter Soldier also stars Robert Redford, Hayley Atwell will return to play Peggy Carter, Cobie Smulders, Georges St. Pierre, Toby Jones and Maximiliano Hernández.

Related Video: Chris Evans Talks Favorite Childhood Superhero

Watch the video to hear what the stars think about attending the craziness of Comic-Con and being ushered into the Marvel world!