Alicia Vikander plays a murder suspect caught in a love triangle in "Earthquake Bird," a thriller set in 1989 Tokyo in which the Oscar winner performs in English as well as Japanese.

Based on the novel by Susanna Jones, the film follows Vikander's character, translator Lucy Fly, an expat living in Japan who begins a romantic relationship with photographer Teiji, played by Naoki Kobayashi.

But Lucy's life is turned upside down with the arrival of fellow expat Lily Bridges, played by Riley Keough, who befriends the couple. Lily disappears, presumed dead, and Lucy becomes the main suspect.

While Lucy appears tough on the outside at first, her psychological fragility soon shows.

The film, which premiered at the BFI London Film Festival on Thursday, requires the Swedish-born Vikander, known for "Ex Machina" and her Oscar-winning performance in "The Danish Girl," to speak in Japanese in numerous scenes.

"I wish I could tell you that I knew Japanese and I learned it in three months," Vikander, 31, told Reuters at the premiere. "I mean I did an immense amount of work to be able to do the Japanese ... and being bilingual I know you can't just mimic words and sounds, you need to really know what you're saying."

"So I did everything from reading my scenes out loud in English and then we kind of reworked on translating them to really get the kind of sensitivity and the emotion and the subtext that I had in my acting, hopefully ... It was a lot of work."

Director Wash Westmoreland, known for dramas "Colette" and "Still Alice," said he was familiar with the setting when he was first approached about the project, having lived in Japan in 1989.

"When I started reading Susanna Jones' brilliant novel I just fell into it, just the psychology was so fascinating and the story's so unexpected and I felt, ‘Aha, I can use this to make a neo-noir,'" Westmoreland told Reuters.

"Earthquake Bird," which will have a limited theatrical run, will be released globally on streaming service Netflix on November 15.