A teenage boy, Bendegúz Regős, who has never succeeded at anything in his life and of whom the only thing people remember is: "I wish they had hanged you when you were two days old", drops out of school and is hired by his mother to be a cowherd with the help of a clutch. That's how he ends up with the harami-faced Bacter Szabo, who has to graze the cows by the railway. But even though Bendegúz is a well-meaning boy, he is usually "in trouble" by the time he has "finished his purpose...". The boy is subjected to a lot of humiliation, even if he has the sense to keep to himself. But his good humour never fails him. In the outskirts of Vecsés and Ferihegy, to make the cows fat, he is forced to graze in a forbidden area, which gets him a good beating from the peasants. But his life is made worse by his bacterial mother-in-law, the Stinky Witch, who turns even clean water into vinegar in his mouth. She is as flat as a flame from the front and as curvy as St. Gellert's Hill from the back.

Based on the true story of a Russian serial killer who, over many years, claimed victim to over 50 people. His victims were mostly under the age of 17. In what was then a communists state, the police investigations were hampered by bureaucracy, incompetence and those in power. The story is told from the viewpoint of the detective in charge of the case.