Fantastic Beasts star Katherine Waterston narrates Katie Kitamura's moody novel, A Separation

Katie Kitamura’s latest novel, A Separation, is a slim, eerie tale about an unnamed woman, recently separated from her husband, Christopher, who is asked to go Greece and search for him after he mysteriously goes missing. Oh, and nobody — including her meddling mother-in-law — even knows they were separating, because he’d asked her not to tell.

Since the narrator is effectively forced into a performance throughout her journey, it made perfect sense to cast Kitamura’s good friend and phenomenal performer, Fantastic Beasts star Katherine Waterston, to read the audiobook. “Katherine was somebody I had in mind as the visual image for the character when I was writing,” Kitamura tells EW. “When she agreed to do the audiobook, I was completely thrilled. She’s not only a brilliant actress, she’s also incredibly, ridiculously smart, and I knew that her interpretation of it would be spot on.”

Funnily enough, Waterston actually considers Kitamura her inspiration for the narrator’s voice. “I had Katie’s voice in my head because I’ve heard her read live before, and I just always felt like the simple, easy way she has in speaking [her work] suited it so well that I basically just ripped her off,” Waterston says. “In the book, she talks a lot about the failure of imagination, and I failed to imagine a better approach than her own!”

For another character, though, the narrator’s pushy, upper-class mother-in-law Isabella, Waterston did look elsewhere for a model. “I heard this woman in a bookstore in London, and I was just fascinated by her voice,” she says. “I was basically snooping on her conversation with the owner of the bookstore, and the few things she said gave me enough information to be able to Google her and figure out who she was, so I listened to some interviews with her. She has a very heightened, posh kind of accent that you really don’t hear too much anymore.”

Waterston says she spent a week holed up in a London hotel preparing for her performance on the audiobook — and though that project is now complete, her work on A Separation is far from over. Announced last week, the actress bought the film rights to Kitamura’s novel and is already attached to star. “Basically I’ve just been waiting for her to write a story that I could turn into a movie,” Waterston says. “I couldn’t be a mixed martial artist in her first book, and the second book is basically impossible to adapt because it’s set in a fictional time and place that’s kind of an amalgam of lots of different places. So I just got the rights [to A Separation]! I’m excited. And I’ve been getting a lot of jealous emails from people who wish that they had done it first.”

Below, listen to an exclusive clip from A Separation. The novel is available in print and audio on Feb. 7.