Kat O'Brien, beautiful and worldly, has chosen God above her handsome and selfless lover and is torn constantly between her vocation and her still powerful attraction for David.
Annie Bliss, innocent and confused, sees the convent as an escape from the poverty and hardship of her childhood. But she dreams of the glamorous world outside the walls and gradually her dream becomes an obsession.
Jane Galloway is the seemingly perfect postulant whom no one likes and whose piety and strange, calm exterior hide a secret life which is beyond imagination.
The tension mounts as the rigorous training becomes more and more demanding and their secrets become more and more difficult to hide. Until finally, those secrets erupt into a climax that could ruin the convent and the lives of all three girls.