Ten-year-old Ole is full of mischief. He attempts to fly and is hospitalized with a broken leg. When he sees a Sherlock Holmes movie on TV, however, he forgets about the pains and comes up with a new plan. Disguised as Sherlock Holmes and Dr. Watson, he and his friend Andreas start searching for criminals. Soon, the two boys detect their first case. On the street they meet a man wearing a stuck-on beard. The hobby detectives find this very suspicious and decide to follow him.

Berlin during the Great Depression of 1929. Unemployed cab driver Emanuel sees no more opportunities for himself in the city and wants to try his luck somewhere outside. His friend Fritz lends him his cab for one last trip. In the process, he meets the dancing girl Susi. She is young, beautiful, carefree, self-confident and persuades him to stay. During a demonstration by the unemployed, a policeman is stabbed to death. Emanuel is suspected. He is arrested in the evening at Susi's revue. Frida and Gerda and other young people with their problems and their longing for a little security and social safety are also there.