Kate Mara Teases The Astronaut, Her 'Thrilling' New Alien Thriller with Laurence Fishburne (Exclusive)

Kate Mara is stalked by creepy aliens while in lockdown at a remote safe house in The Astronaut, a new sci-fi thriller from writer-director Jess Varley.

PEOPLE has an exclusive first look at the movie ahead of its world premiere at the 2025 SXSW Film & TV Festival this Friday, March 7, showcasing Mara, plus costars Laurence Fishburne and Gabriel Luna.

Mara, 42, plays Sam Walker, the titular astronaut who, upon returning home from her first space mission, starts witnessing otherworldly occurrences while staying under NASA's care at a remote, high-security safe house.

Soon, she "fears that something extraterrestrial has followed her back to Earth," as the synopsis teases.

Varley tells PEOPLE the claustrophobic thriller relies on Mara's "strong" lead performance, praising the A Teacher star for "carrying" the film.

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For Mara, the "highlight" of the project was sharing scenes and bonding time with costar Fishburne, 63, who is also an executive producer on The Astronaut.

"He is the greatest storyteller ever," says Mara. "We had never met before, but by the end, any time in between scenes or setups, it didn't matter how long we had, whether it was five to an hour, we would sit in the green room and just talk about acting."

"It was so incredible to work with him because he has such passion and such joy and love for acting, still today. He's been acting since he was a tiny kid," she continues. "I feel very much like that as well, and I've been acting since I was little too. To see somebody that I really look up to who really still feels the joy and really shares the joy with everybody, it's so amazing to see."

Mara's other scene partners are, of course, aliens that lurk in the shadows throughout. "I gotta say, in the room they are not very giving," she jokes of the creature costars. "I was basically looking at nothing. Maybe there was a tennis ball at some point, or I think we used a tree branch maybe at one point as well."

"I really had to use my imagination and really rely on Jess and her vision. If I was ever struggling with what I was meant to be seeing, I really felt like I could rely on Jess because her vision has always been really specific and clear, which is so useful. That's not always the case."

"For something like this, if you don't have that for the actor, it's really impossible to go to the places that she's asking you to go to," says Mara.

According to Varley, she wanted the aliens to be "rooted in earthly elements" rather than "feeling super sci-fi or unrealistic." The filmmaker explains that a "big inspiration" was bioluminescent sea creatures and how "ethereal and otherworldly they feel." She adds, "Even the sounds [the aliens] make are references to the sounds that whales make."

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Another major component of The Astronaut is the ultra-modern, state-of-the-art safe house that houses all the suspense. "It was a really nice place to go to work every day because we really were surrounded by such a beautiful environment," Mara says of the location they found in Ireland, where they were for the "two peak weeks of autumn," adds Varley.

"No one had ever shot in this house before; these are not film people who own the house. So they were very gracious to host us," says Varley. "I had been really drawn to very modern architecture, and I loved the idea of a really dark-black, inky interior."

Mara describes the twisty film as a "very thrilling experience" that "feels very much like a roller coaster." Teases Varley, "People can look forward to an unexpected ending."

The Astronaut will have its world premiere at the 2025 SXSW Film & TV Festival on Friday, March 7.