A romantic story about Jakub, a student in the summer camp, and his teacher Klara.

The fairy tale is based on two fairy tales by Božena Němcová, "Righteous Bohumil" and "The Black Princess". It tells the story of a weak king and his wife, whose desire for a child leads her to a conspiracy with the devil. The princess, who grows up under the influence of the "impure" powers, only escapes from their power thanks to her love for the fisherman Radek.

Even great love does not necessarily overcome a difference of morals - although the young hero is very much in love, he still rejects the comfortable and easy existence he could lead thanks to the family of his future father-in-law. A tediously moralistic comedy, it picks up with all seriousness the morality of a socialist man who has broken forever with petty bourgeois ideas. It is therefore too contrived, nor does it succeed in elevating the tawdry story in any way. A comedy about life's little and big compromises.