This romantic story turns on a stirring infatuation that takes hold of three young people under the influence of Simon, a Prague student. After the study year, 18 year-old Julio returns to his parental home, a little chateau on the Otava river. There he converges with his childhood friend Petr and the young boatman's daughter Klárka. Sharing her beguilement with Simon, who has quickly turned a tranquil summer atmosphere into a relationship drama, is Julio's cousin Rosa.

You will meet the family of the miller Kaliba, who is proud not only of his mill, but also of the family tradition, according to which the milling profession has been passed down at the inn's mill for almost three hundred years. And since Mr. Kaliba has no son, it is certain that his only daughter Liduška must marry a miller. Perhaps this would have happened if the Kalibas had not gone to the anniversary exhibition. Here, Liduška meets the handsome engineer Karel Loukota, who is an overly zealous member of the cycling club "Don't Get Married!", but is not immune to love at all. Of course, he will face many hardships and obstacles, the biggest of which is, of course, the miller Kaliba with his fierce efforts to uphold the family tradition...