Sandro is a well-known journalist and he is conducting a survey on human selfishness. Every man and every woman he meets turns into a theme for his inquiry. Even his own wife, Titta.

A middle-aged plumber quits his job and questions his life after seeing somebody his own age suddenly die from a heart attack on his way to work.

Gabriella, a maid, wears a jewel at a dancing party which belongs to her mistress, and when it is stolen she is accused of the theft and sent to jail. Some other maids organize a search party for the real thief who seems to be a moustached youth who continually sings a popular song.