Lucia Spinelli, orphaned by both parents, is taken as a housekeeper in the house of Mrs. Carla Parodi, when she reaches the age of majority, the young woman is almost forced to marry Mrs. Carla's brother. After the marriage and the birth of the first child, Parodi's intrusions on the life of the two spouses continue.
The film is set in Naples. Two doubles, an American and a Neapolitan, alternate visiting Zaza, the maid of a magazine company, deceived by their resemblance.