Germany in the mid-1950s: Dr. Seidel (Rühmann) is a successful teacher at a high school in a provincial town.

On arrival at his new working place he is hit by a student while trying to settle a quarrel among youngsters in the schoolyard.

While trying to establish discipline, Dr. Seidel makes himself quite unpopular; he even becomes the target of intimidation attempts by a former student (Löwitsch), who is now a gang leader with criminal ambitions.

In a side story Dr. Seidel courts the older sister (Frydtberg) of a student but his advances are unsuccessful, so he falls back to a co-teacher (Löbel) living next door in the same boardinghouse.

Another resident at the boardinghouse is a wrestler (Fröbe) who teaches him wrestling skills in exchange for literacy lessons.