Melissa Leo, 57, stars as the Reverend Mother in the upcoming film Novitiate. The film follows Margaret Qualley as Sister Cathleen, a young woman from Tennessee who decides to commit her life to God and join a convent. There, she meets the Reverend Mother and faces many challenges in the novitiate stage of becoming a nun.

“Most of the story takes place in the early 1960s, there’s a little precursor where a younger actress or two who plays younger versions of Margaret Qualley’s character, who in fact leads the film, beautifully I will add,” Leo told uInterview exclusively. “Margaret decides against her mother’s better judgement to join the convent, and I am the Reverend Mother and in charge of Margaret. And the Reverend Mother takes that task seriously. She has a house of teenage girls and she has been doing her best for 40 years to train them to be good nuns, in a system she has a great belief in, and for poor dear Reverend Mother when our story begins, Vatican II has landed on her desk and she is taking it in its very worst context.”

Leo points out the the Reverend Mother is a somewhat scary figure, who uses a whip to help teach. “Most people that I speak to if they feel they know somebody like the Reverend Mother, I say to them, they do not know anything like the Reverend Mother because in fact what they know is probably a teacher from a Catholic school, and the teaching nuns are a very very different breed of nun that the convented nuns, and what’s really remarkable about the film is how you feel like you go inside this convent in the early 60s,” Leo explains. As for using the whip, the actress says it is hard to judge. “The Reverend Mother is the wife of God. [The whip] is something that the Catholic Church may or may not have had, self flagellation… I believe although, I do not know, that in Vatican II that was one of the reforms that was discussed and changed.”

Leo describes herself as an “actor’s advocate,” who makes sure that everyone, even the extras on set, is treated fairly. “The challenge is for me as an actor when I saw all those extras in Tennessee sitting in much too much smoke for much too long, when I saw those extras kneeling on their knees on those cold stone floors without any knee pads and I said we’ll stop until we get them kneepads,” she said. “I’m an actor’s advocate when I work, and to have that little brood of the young speaking roles and Margaret Qualley, their looking up to me as an actor was a delight to me and a delight to work with those extras down there, those very very hard working extras that really, again, make the film feel like you are really getting to know who these women are.”

Novitiate came out Oct. 27. See the trailer below.