When twenty-eight-year-old Sister Monica Wickes leaves her small town convent life to study theology in the Bronx, she expects her biggest challenge to be the temptation to glance at her reflection in the tiny mirror above the sink in her new dormitory room. But it's 1965, and tough to stay conservative, even for a nun.

By the end of her first two days at Saint Albert's University, Sister Monica has met the changing times head on, questioning all aspects of Catholic life, wondering how she can live out her vocation as the church becomes more worldly. Even the chaplain, Father Malbert, seems eager to move away from traditional teaching and customs, abandoning the Roman collar in favor of khakis and knit sweaters.

Sister Monica's also faced with three situations requiring immediate attention. Her younger brother, Timothy, has violated his parole. A male classmate, Aidan Connors, has inspired feelings that are questionable for a woman with a vow of chastity. And, most upsetting of all, Mother Ignatius, her new superior at Saint Lucy's Hall dormitory, dies in her sleep before keeping an appointment with Sister Monica to discuss trouble in the house.

Sister Monica thinks Mother Ignatius' sudden death is remarkably convenient for too many people. As she explores the possibility that Mother Ignatius was murdered, Sister Monica uncovers even more secrets and motives and endangers her own life.