Pepe Nietnagel and his fellow students of the Mommsen school come up with all kinds of ideas to get out of doing any actual school work. This includes simulating suicides, setting off the air-raid sirens and abusing the school director's new broadcasting system. They succeed in sending their teacher to a sanatorium and get a replacement that turns out to not be so bad after all.

The 13-year-old Ludwig is to have for every joke. At boarding school he cuts his stern teacher, Captain a. D. Semmelmaier, during the nap from the beard. The angry pedagogue then sends the spoiled flail back to his beloved Bavarian village. The long-suffering mother persuades the rector to resume her reforming boy at the Latin school. Everything seems to be working out for the better, but the upcoming marriage of his sister Ännchen with the Berlin beer brewer Karl Schultheiss presents Ludwig with new challenges.

The quiet life of an extended family is shaken up when a circus comes into town.