The end of the 1950s: Rosanna returns as a music teacher to the claustrophobic confines of the convent boarding school from which she escaped as a young girl. Her happy, understanding ways, unconventional teaching methods and deep love of music soon win her the hearts of her girl pupils. Vithold, a nice young doctor, is also fascinated by Rosanna and gradually manages to convince her of his deep feelings for her. Rosanna encounters rejection and hatred from Alberta, the Mother Superior, who has a deep belief in strict discipline and order, as well as from her close associate Sister Federica, who is severe to the point of inhumanity.