Mania is the illegitimate child of a girl from the suburbs of Krakow and a lawyer. Bowing to the will of the family, he abandons the girl, leaving a large monetary "compensation". The girl dies, but before she dies she leaves a certain Mr. Majcherek a letter and a document, proving that Mania will be able to receive the money when she comes of age. The dishonest Majcherek (knowing the contents of the letter) must therefore wait 20 years to be able to apply for Mania's hand and thus come into possession of her property. Unaware of anything, Mania lives in the suburbs with Maciejowa (who took her in as a child) thinking that she is her daughter. When Majcherek begins to adore Mania it turns out that she already has two rivals - boys from the neighborhood. That's when the fourth one appears - handsome Zygmunt. Mania loses her head for Zygmunt. What she doesn't know is that he is in fact her real father's upbringing....