Maria loves singing and longs to be a nun, but her free-spirited nature keeps breaking convent rules and troubling the nuns.  The Mother Abbess decides to send Maria to a Captain's home as a governess for his seven children.

There, Maria faces the Captain's strict military rules and the children's pranks.  Yet, with her genuine warmth and the power of music, she melts the children's defences and breathes new life into the cold household.  Her charm eventually wins the Captain's love, leading them to marriage.

However, their happiness is threatened when Austria is annexed by Nazi Germany.  Refusing to bend to the regime, the patriotic Captain decides to flee the country with his family, planning a daring escape under the cover of a music festival performance......