BOB ABERNETHY, anchor: Now, a rare and remarkable look at a young woman's life as a novice inside a Catholic convent near St. Louis, the Carmelite Sisters of the Divine Heart of Jesus. Filmmaker Diana Frank followed a novice there for nearly two years -- up to the taking of her first vows, of poverty, chastity, and obedience.

Later, Sister Mary Xavier, the name she took, and several others from the convent left to try to start a less sequestered order. But she says she remains committed to a religious life.

Sister MARY XAVIER (Novice, Carmelite Sisters of the Divine Heart of Jesus, St. Louis): When I first entered the convent, it was so different. It was like a culture shock. Everything was just so holy. It was like walking into another world. I didn't really have a desire to go into a convent and never see anyone again. I didn't want to be a nun. I mean, I had so many other things I wanted to be. I wanted to get married. I wanted to have kids. I wanted to be a normal person. You know, what everyone else does -- what all my friends are doing: going to school, and having a career, and all that kind of stuff.

I want to have an impact on the world, and I wanted to be somebody. I had all these dreams, and all these aspirations that I wanted to do and to be. Like I love acting. I love theater, and you don't really get much of that in the convent.

The convent was like, you know, throwing your life away. But I still felt that tug. I knew it was something in me. You know, I just knew it was God saying, "I want this."

My father, I would say, just did not want me here.

JESSE MCCULLOUGH (Father of Sister Mary Xavier): We lost a son. It was like cutting off an arm, you know. And then, when she goes away, it's like cutting off another arm. You're hurt, you know. You think you're not going to see her again for a long time. You know, you're not used to that. You know, you think, "Me -- why's this happening to me? Why am I losing another child?"

Sister MARY XAVIER: They were so against it. Like I would get letters, and, you know, "you shouldn't be there, you're throwing your life away," and all this. It was hard. A number of times I cried over those letters.

I'm a novice -- a second-year novice. The novitiate, it's a time of intense preparation, intense formation, that you're going to be religious and stuff, and so it's a kind of stripping away of all your attachments to, like, to the world. On December 8, that's when I make my first profession. The profession of the three evangelical councils are vows, which are of poverty, chastity, and obedience.

Sister MARY LELIA (Novice Mistress, Carmelite Sisters of the Divine Heart of Jesus, St. Louis): The three vows kind of are an epitome of what the whole life is going to be. All of your life before this moment of the taking of the vows is kind of a preparation. It all comes up to that moment. Everything in your life is going to flow from that moment. Chastity -- chastity can have a very negative connotation.

Sister MARY XAVIER: In high school I dated a little bit. But it was nothing major. I was never, like, in love or anything like that, like I was going to marry a boy or something.

Sister MARY LELIA: Chastity is a freedom. It's a freedom to love more purely, more perfectly. And the three vows are how we bind ourselves to him. Poverty in the negative sense is that I cannot use anything without asking permission for it.

Sister MARY XAVIER: Like me and my brother would spend weekends at the mall. It's all we would do, is shop for clothes. But I love clothes, clothes and shoes.

Sister MARY LELIA: We can be so greedy. And poverty is to help us be free of greed so that I can again attach myself more completely to Christ. And then the third vow, obedience, which for some congregations, that's the only vow they take, because it encompasses everything. Part of obedience is, I am not to determine anymore that I do this or do that -- where yourself is going to be. It's not going to be choices you make, which people you're going to work with.

Sister MARY XAVIER: What toothpaste I use.

Sister MARY LELIA: That's right, that's not the choice you're going to make. This period's going to decide. This is how you're going to use your talents. I give my talents to God. It's not for me to determine.