Based on an authentic case from the 1920s. The head country constable Heinz Lippert arrests the Polish farm worker Jakubowski on suspicion of murdering a child - his adopted son. Although he has insufficient evidence, public prosecutor Becker takes the case to court. Jakubowski is sentenced to death, the "Polish murderer" fits in with the propaganda of the time. Lippert, encouraged by the communist editor Hartmann, tries to prevent the sentence from being carried out and even investigates the real perpetrator. In vain, the death sentence was carried out prematurely. After the Nazis seized power, the public prosecutor, now an SS leader, had the men who had uncovered the true facts arrested. Lippert joins the underground resistance.