A few years ago on Dec. 1, Lily Gladstone received the call that she was chosen to play the historic Osage woman Mollie Burkhart in Martin Scorsese’s epic “Killers of the Flower Moon.” That day also happened to be Burkhart’s birthday.

As Gladstone noted during a Variety Screening Series conversation moderated by senior awards editor Clayton Davis, the call came on that day “by nobody’s design,” and she found it a fitting and meaningful coincidence.

“It felt like maybe there was a responsibility that was not really up to me, but was important that I receive,” Gladstone said. “So because it happened that way, it was like an immediate connection to the person that I was playing.”

Historical archives are not rife with biographical material on Burkhart, who is one of the survivors of the Oklahoma Osage murders that took place in the early 20th century. Outside of court documents and photographs, Gladstone looked elsewhere to fill in her character. In addition to speaking with Burkhart’s direct descendants, she was reminded of her own family, drawing parallels between Burkhart and her great-grandmother Lily.

She said of the two women, “They were born within 10 years of each other, saw this great transition happen, had families, both were pretty devoutly Catholic. So that kind of interesting little cocktail in worldview.”

Shooting “Killers of the Flower Moon” was one of Gladstone’s first experiences spending an extended period of time in Oklahoma, and she acknowledged that the Osage tribe had also not been there long at the point in time when the film takes place, as they had been forced to relocate from their original land.

Tantoo Cardinal, who plays Burkhart’s mother Lizzie Q, spoke to how her personal experiences as an indigenous woman informed her performance. “The approach to my character’s story is kind of my history. I come from that world where people have been seriously ripped off. I come from that world where women’s lives are in danger. I come from the world of genocide, colonialism, femicide. It’s in my blood, it’s in my bones, it’s in my world. So that was my preparation.”

John Lithgow, who plays a prosecutor named Peter Leaward seeking justice for the Osage tribe, joined the cast just about a month before shooting wrapped. He lamented the fact that he wasn’t able to spend time with more cast members, as many characters had died by the time Leaward arrives in the film and most of his scenes were with “all the white guys.”

Lithgow said of his experience on set, “Basically, I was the newcomer and the kind of outsider, being the prosecutor, being the man who’s trying to bring justice to this astoundingly unjust story. It made me an outsider and I felt that way in many ways. It was a beautiful role because it was sanity arriving — and very, very close to the end.”

Janae Collins said of building the familial dynamic between Burkhart and her sisters, “It’s an interesting story with that because all four of us grew up as only children for the most part. So understanding the dynamic of the sisters was a process for us. We watched other sisters in the Osage community because they have a very particular birth order and kind of personalities that emerge with the birth order.”

Jillian Dion added, “We just started to hang out and realize there was a really fluid dynamic between the four of us…It felt like home already when I was with these women and it just felt natural.”

Watch the full conversation above.