[Source: AP Entertainment]

Eileen, the title character of Ottessa Moshfegh’s debut novel, is a strange young woman with a vivid, sensual, and sometimes dangerous imagination.

Her actual life, however, is anything but: She works a mind-numbing desk job as a secretary at a boy’s prison in Massachusetts in 1964 and goes home to a depressed, cruel father who seems content to drink himself to death. She is hopelessly lonely and a little bitter — that is until the arrival of a glamourous new employee, Rebecca Saint John, a Hitchcock blonde with a doctorate from Harvard, a taste for martinis and a breezy Mae West confidence.

The moody, noirish film adaptation of “Eileen” debuted on Saturday at the Sundance Film Festival with New Zealand actor Thomasin McKenzie playing Eileen and Anne Hathaway taking on the role of the enigmatic Rebecca.

As Moshfegh said in an interview Saturday in Park City, “Rebecca sort of sweeps and carries Eileen and the viewer away into something that is really kind of sticky.”

Moshfegh helped adapt her novel for the screen. Before work even began on the script, she, her husband Luke Goebel and director William Oldroyd, behind the terrific “Lady Macbeth” with Florence Pugh, settled on an “eerily perfect shared vision” steeped in the genre but subverted with a contemporary character lens.

Though she knew the story and the characters by heart, when she and Goebel began writing the script, suddenly new dimensions opened up in characters like Eileen’s father Jimmy, who is played by Shea Wigham. The actors then added their own dimensions.

As Eileen, McKenzie had to do a lot of heavy lifting in translating the largely first-person novel into a performance that wasn’t aided by an inner monologue or exposition.

McKenzie came in as a fan of Moshfegh, having already read “My Year of Rest and Relaxation” and then “Eileen” and empathized deeply with the character’s longing and loneliness. She dreams of a bigger life, the possibility of which seems to open up to her in the form of Rebecca.

Hathaway, on the other hand, needed to go big to play Rebecca, whose name is a nod to Alfred Hitchcock’s adaptation of Daphne du Maurier’s book. Moshfegh wanted her to be larger than life in the film, too.

Due to COVID-19 protocols, Moshfegh and Goebel weren’t able to be on set during the filming, but they did get to tour Eileen’s house the day prior. It was a transportive experience.

During a climactic scene, Hathaway even had an out-of-body experience.