The funny clown Bratislav Metulskie is found dead in circus "Apollo". The retired commissioner 00 Schneider is asked to assume control of the case. Schneider and his aged sidekick Körschgen investigate to find the murderer.

Before WWII: Dr. Hasenbein lives with his son Peter in a small town. Aunt Uschi's orphanage houses many children and a hamster. When the hamster falls ill, Dr. Hasenbein is given something to do. The tailor, Mr. Voss, is also treated by Dr. Hasenbein: for tendinitis. During the war, Dr. Hasenbein has to go away. When he comes back after 30 years, everything has changed...