An Italian submarine commander manages to sink an English warship and take its very British commander as prisoner. The film is based on the relationship which develops between the two characters.

Three girls are on a hitchhiking trip through northern Italy, the riviera, Venice, Pisa and Rome.

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.

An old gentleman, a direct descendant of Zorro, has a single son named Raimundo in whom there is no trace of proud pride.