J.J. Abrams’ projects are known for their high levels of secrecy, and Mary Elizabeth Winstead says the filmmaker’s upcoming Cloverfield follow-up, 10 Cloverfield Lane, was no different.

“There is this veil of secrecy to it from the very beginning,” she said at EW’s SAG Awards party in Los Angeles on Friday. “We were making this movie in this little bubble where nobody else knew what we were doing and there’s really only three actors in the whole thing, so it kind of felt like this really intimate experience. Now that it’s about to come out, it’s sort of crazy — like, ‘Oh yeah, people are excited to see this movie.’ I forgot that that was going to happen.”

Winstead is one of the three stars in the film (which Abrams has described as a “blood relative” of his 2008 monster movie), alongside John Goodman and John Gallagher Jr. Building suspense in a film with such a small cast, she said, was akin to working on a play.

“It’s so much about just the actors interacting with each other and that tension that builds, just all wondering if they are who they say the are, if they’re telling the truth or not, and really wondering what’s outside,” Winstead explained.

And the actors do know what’s lurking outside. “We always have the script. We know where it’s all leading to,” she told EW. “As production went on there were rewrites, as there usually are, but nothing that was major. It was always something that I knew we weren’t going to be able to talk about until people saw the movie.”

Production on 10 Cloverfield Lane coincided with Abrams shooting Star Wars: The Force Awakens, but that doesn’t mean the cast got any inside information on the galaxy far, far away.

“Oh no, he keeps it on lockdown for sure,” said Winstead. “There are no secrets coming out of that guy.”

10 Cloverfield Lane arrives in theaters March 11.

—Reporting by C. Molly Smith