Mara, Silvia and Irene, three sisters, are sent from Rome to Padua as guests of prof. Bordignon, their uncle. First, they let off steam with the young cousin Anselmo; then, realizing that their destiny is a boarding school, they take plot their revenge.

Andrea, a nice girl, move from Veneto (north of Italy) to Roma. She is employed as a nurse in a medical practice. She soon is involved in a never-ending game of misunderstanding, couples exchange, sexual seductions.

It's a night like any other for Captain Marco Giordani, or so he thinks until Silvia has a fight with her companion and ends up alone in the middle of the station square. Giordani offers to help her, and soon finds himself entangled in a murder case.