Writer-director Margaret Betts "Novitiate" is a spiritual drama following 17-year-old Cathleen (Margaret Qualley, "The Nice Guys") as she falls hopelessly, giddily in love. But it's not a boy -- or any other human -- who's captured her heart, it's God.

Much to the bewilderment of her entirely non-religious mother (a terrific Julianne Nicholson), Cathleen freely enters herself into the grueling training to become a "bride of Christ," all but abandoning every aspect of her previous life. Joining the Order Of The Sisters Of Blessed Rose convent, she surrenders herself to the church's intimidating Reverend Mother (Melissa Leo), who rules over her charges with an iron fist.

Cathleen's entry into the covenant coincides with the reforms of Vatican II, which set out to take a hard look at the practices of the Roman Catholic Church and update it for a modern era. This changing ideology radically altered the role nuns played in the church, a shift which upends the Reverend Mother's world, causing her behavior to spiral further into sadism.

Melissa Leo's performance has garnered a lot of praise as "Novitiate" has made the festival rounds, and she certainly goes big with the role. Her work walks a fine line between compelling and being just too much, and I'm not convinced she always remains on the right side of that line. Thankfully, Qualley's more subdued, but entirely wonderful, performance helps to balance out Leo's scenery chewing.

Betts's film admires the hard, selfless work the women do to prove their faith, even as it questions whether their sacrifices are worth surrendering their entirely human desire for intimacy. Through Cathleen's eyes, "Novitiate" becomes a captivating examination of belief, devotion, sexuality, and spirituality.