When the bank clerk Klaus Helwig is arrested on suspicion of embezzlement, his son Heintje, whose mother died at birth, comes to his grumpy grandfather's house. Heintje manages to win his heart and prove his father's innocence..
A new teacher, Dr. Dr. Bach, is transferred from his quiet village elementary school to the Mommsen Gymnasium, bringing along his nephew Jan. Bach's lackadaisical methods raise the suspicions of the other teachers.
