Robert Pattinson knows you want to talk about the "sex box."

In his creepy, kinky new sci-fi drama "High Life" (in theaters Friday in New York and Los Angeles, expands nationwide April 19), the actor plays a prisoner aboard a doomed spaceship, where he and his fellow ex-convicts are unwilling participants in a reproduction experiment led by a debauched doctor named Dibs (Juliette Binoche). Every day, the men are expected to masturbate in a metallic chamber known as the "sex box," donating their sperm in hopes of impregnating one of the women on board. Dibs also outfits the room for her own self-pleasure, with rope, fur and a giant metal sex toy.

The salacious enclosure became an instant talking point on Twitter when the movie premiered at the Toronto International Film Festival last fall.

When Pattinson read writer/director Claire Denis' script for the first time, "I was like, 'Wait a second? What is this?' " he says with a laugh. "I was fascinated. I knew it was going to spark a conversation."

In reality, the room constructed on the set "sort of looked like a public toilet with a dildo chair," he adds. "I was like, 'Claire, this is quite a literal interpretation of a sex box.' The art department spent a lot of time in sex shops getting various objects for it."

But "High Life" is more than just space erotica. The unsettling thriller centers on the dejected, world-weary Monte (Pattinson) and his infant daughter, Willow, the last two survivors on a spacecraft hurtling toward a black hole. As the story flashes back and forth in time, the mystery unfolds about how Monte's crewmates met their ends, but also how Willow's improbable birth came to pass.

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Pattinson, 32, was drawn to the story because "it presented itself as a puzzle," he says. "You had to sort of feel your way through it without really knowing what the exact rules of the script were."

Denis, a prolific French filmmaker making her English-language debut with "High Life," initially conceived of the project years ago with Philip Seymour Hoffman and Patricia Arquette in mind to star. Although she envisioned an older actor to play Monte, she changed her mind after talking to Pattinson.

"I was struck by him," says Denis, who first saw him as vampire Edward Cullen in the "Twilight" movies. "He's probably more intelligent than me ... and has this extraordinary quality of being a great actor, but there's always a sense of mystery beneath."

Before they met, "I read the Wikipedia on 'string theory' and tried to (rationalize) some reason why this character would not age because of spacetime," Pattinson says. "She hadn't heard that before and she loves romanticizing these kinds of ideas in physics. So it was my one card I had to play, and I was like, 'Wow, that actually worked.' "

Aside from acting, Pattinson took a hands-on approach behind the scenes: He recruited his best friend's infant to play Willow when the twin babies initially cast wouldn't stop crying during rehearsals. He also sings the movie's haunting closing-credits song, "Willow," which he recorded with alt-rock band Tindersticks. Although he has similarly contributed music to the soundtracks of his films "Twilight" and "Damsel," he has no lingering rock-star ambitions.

"I used to play gigs all the time and have always said I'd love to again," Pattinson says. "But there's a strange stigma with actors trying to do music, and it is something quite frightening to me. I've learned how to deal with criticism in film, but I’m very vulnerable to it in music. I don’t know whether I’m willing to take the hits – I prefer to have an audience of one or two (friends)."

Not that he has any room in his schedule for a second career. He recently finished shooting Netflix's Henry V drama "The King" with Timothee Chalamet, premiering later this year, and will spend the rest of 2019 in production on Christopher Nolan's highly anticipated follow-up to "Dunkirk," expected in theaters July 17, 2020.

The actor says he's "sworn to secrecy" about the project, which has been described as a "massive, innovative action blockbuster."

"I got locked in a room to read the script – I don't have it myself," he says. "I've been a little wary of doing big movies for years and years, but there's just something about Chris Nolan's stuff. He seems like the only director now who can do what is essentially a very personal, independent movie that has huge scale. I read the script and it's unreal."