Dec. 16 (UPI) -- Mank star Amanda Seyfried says her role in the film was her "biggest challenge to date."
The 35-year-old actress discussed playing Marion Davies in the new biopic during Tuesday's episode of Late Night with Seth Meyers.
Mank depicts screenwriter Herman J. Mankiewicz's (Gary Oldman) struggle to write the classic 1941 film Citizen Kane while contending with director Orson Welles and issues in his personal life. It also explores Mank's relationship with news magnate William Randall Hearst, who inspired the Citizen Kane character Charles Foster Kane.
Davies was an actress, writer and producer who was romantically involved with Hearst until his death in 1951. On Late Night, Seyfried said she immediately knew Davies would be a "juicy" role.
"I kinda knew it was juicy part before I knew I was cast, because I had just read the script and I thought, 'God, what a dream role,'" she said. "The idea of stepping into the '30s and playing somebody who I didn't really know ... It's very daunting, very exciting. Definitely the biggest challenge to date."
Seyfried also discussed working with David Fincher, who directed Mank based on a script by his late father, Jack Fincher. Fincher, known by many to be an exacting director, has also directed such films as Se7en, Fight Club and Zodiac.
"I didn't really have any expectations," Seyfried said of working with Fincher. "I knew we were going to do a lot of takes and that sounds a lot like rehearsal for a play, so bring it on."
"He's so supportive of his actors. He's so respectful. He knows how much we're bringing to the table," she added. "I mean, we're bringing his characters alive in his movies and he has a gentle hand in guiding you through the moments and getting exactly what he wants without being a brute or anything like that."
Mank opened in theaters in November and premiered on Netflix this month. The film co-stars Lily Collins, Arliss Howard, Tom Phelphrey.
Seyfried is known for such films as Mean Girls, Mamma Mia! and Les Misérables. She will star in the upcoming films A Mouthful of Air and Things Heard and Seen.