The film is set in 1911 at a Roman Catholic parish in the rural town of Solon, Michigan. Sister Rita (Quinlan), a young nun, arrives at the parish to help run the church school. When the parish's two elderly nuns contract tuberculosis, Sister Rita is forced to move into the rectory that is home to Father Rivard (Van Dyke), the parish priest. The close proximity between the two begins to set off gossip and suspicions, to the point that a monsignor from the diocese (Bolger) comes to give Father Rivard a talking-to. The gossip turns out to be correct, as the priest and the nun confess their love for each other. However, their declaration of emotion leads to tragedy.