Jessica Chastain spoke to Entertainment Weekly about her top-secret role in the new X-Men film, Dark Phoenix. 

“I don’t know what I can describe about this character without giving everything away,” she said. What EW does know, however, is that the role isn otherworldly shapeshifter who influences Jean Grey/Phoenix for her own agenda.

X-men writer Simon Kinberg said, “Her character is way way smarter than we are. What she realizes is she can use [Jean Grey] to manipulate this world, to turn it against itself.”

Jessica and Simon first worked together in The Martian: “I was really excited for him to have his directorial debut and also it was the script,” she said. “I’ve always wanted to do a big comic book franchise-y film but I had some issues with the female characters in the films I was being offered. I was really pleased with this script because I think it’s a departure from the norm.”

Read more at EW.