Diane is due to be married but unsure of her feelings for her husband to be and her strong feelings of faith, she shocks her family by deciding to enter the Santo Spirito convent as a postulant.

New to the school and coming from a broken home, Frances struggles to find friends, and a place in the stratified world of boarding school.

Vatican II causes turmoil in the Order with its instructions for change and simplification within the Church. A lay teacher arrives at the convent.

Rosemary, a student at the convent school, struggles with her own awakening independence and education about her sexuality, from which she has been sheltered.

Sister Paul is a born teacher who joined the convent at 18 and is happy in her vocation. At 24 she goes home to attend a family wedding and meets up with radical priest, Jack Delahunty, who changes her life.

While Mother Ambrose is in Rome, Agnes is in charge. She asks Catherine to teach the official line against contraception and Catherine begins to find the compromises she is forced to make as a nun almost overwhelming.