Melissa Leo Previews Her Oscar-Worthy Performance as a Sadistic Nun in 'Novitiate' Clip (Exclusive)

Margaret Qualley of HBO's 'The Leftovers' and Julianne Nicholson co-star in the period religious drama, which arrives in theaters on Oct. 27.

In the period drama, Novitiate, the titular term -- a prospective member of a religious order who has yet to prove herself worthy of taking vows -- refers to Cathleen (Margaret Qualley of HBO's The Leftovers), an idealistic young woman who joins a convent, the Order of the Sisters of Blessed Rose, ruled over by Melissa Leo's authoritarian nun.

In this exclusive clip, debuting on ET, Cathleen's mother, Nora (Julianne Nicholson), confronts the Mother Superior of the cloister about the treatment her daughter is receiving, though the women have a difficult time seeing eye-to-eye. "It's Mother. Or Reverend Mother," Leo coolly chides. "I'm not a Miss, or a Mrs. either, for that matter." To which Nicholson replies, "Lady, I am not calling you Mother."

Sony Pictures Classic

Novitiate premiered at the Sundance Film Festival earlier this year before screening at last month's Toronto International Film Festival, earning Academy Award winner Leo (The FighterBest Supporting Actress consideration ahead of next year's awards season.

The film marks the feature debut of Maggie Betts, who reveals in her director's statement that she is not Catholic and never particularly gave much mind to religion until she read a biography of Mother Teresa and "her turbulent love relationship with her husband, God." Betts writes, "I honestly didn't have a clue before this, that nuns are actually married to God...that nuns are deeply romantic and intensely emotional people."

Watch the trailer for Novitiate:

And here is the official synopsis:

"Spanning over a decade from the early 1950s through to the mid-60s, NOVITIATE is about a young girl's first initiation with love, in this case with God. Raised by a non-religious, single mother in rural Tennessee, a scholarship to Catholic school soon finds Cathleen drawn into the mystery and romanticism of a life devoted to the worship and servitude of God.

"With the dawn of the Vatican II era, radical changes in the Church are threating the course of nuns' lives. As she progresses from the postulant to the novitiate stage of training, she finds her faith repeatedly confronted and challenged by the harsh, often inhumane realities of being a servant of God. Cathleen finds herself struggling with issues of faith, sexuality, and recent changes in life of the Church."

Novitiate opens in Los Angeles and New York on Oct. 27.

Latest News