Was it an act of sabotage or willful negligence? The non-party engineer Heinz Solter is suddenly arrested and accused of approving a defective pipeline that caused a half million loss to his company. At first, the case seems clear-cut for the state prosecutor, but when he probes deeper, he discovers that Solter had acted against his better judgment due to the pressure from his career-driven and authoritarian boss.

Uli has found an old book in the attic of the Kulturhaus that tells of the exploitation of the peasants by the feudal lords. He tries to imagine how the robber barons would fare in a socialist village. Then two of this type step out of a dusty picture and Uli joins them on their way to the village. There they fail miserably with their overbearing behavior, and even a break-in turns into a failure.

The devil is trapped in Kasper's fridge, but it is stolen by robbers and the devil escapes. He steals Kasper's car and flees. Kasper pursues him to hell and has a friendly conversation with the devil's grandmother. She decides that Kasper will get his car back and the devil will be punished with house arrest.

The devil's grandmother sends her grandson to visit the Punch and Judy family. The devil hypocritically promises to behave in an exemplary manner, but does the opposite. He secretly eats the pudding, smashes the bowl, lies through his teeth and flees when he is caught by the policeman. Punch and the policeman pursue him and catch him with great difficulty. The adventure ends with a clear defeat for the devil and the devil's grandmother's anger at her clumsy grandson, who has once again been caught out.

The devil wants revenge on Kasper for his last defeat and kidnaps Gretel in a helicopter. Kasper uses all the possibilities of modern technology to find and free Gretel, but the devil always manages to shake off his pursuer. He insidiously saws through the bridge and Kasper and his Trabant plunge into deep water. The devil sees himself as the winner, but has not reckoned with Kasper's determination and the reliability of the little car. In the end, the evil kidnapper is defeated and locked in the fridge.

A Saturday evening dance in the village pub is interrupted when the barn of local farmer Paul Gäbler catches on fire. The farmer himself is soon found – hanged. Sawmill owner Züllich claims that Gäbler committed suicide because he was forced to join an agricultural production cooperative, but others are convinced Gäbler was murdered. Officers Schneider and Anders must navigate their way through a complex maze of personal and political motivations in order to reconstruct the crime.

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.

The devil begrudges Kasper his beautiful house. He wants to capture him and force him to build a new devil's house. But Kasper is clever enough to let the devil do all the work himself. The Kasper family succeeds in freeing Kasper and shooting the devil into the clouds.