Berlin, 1917. Director Bredow of Telefunken wants to interest the military in a secret project: a radio device that can transmit not only Morse code but also voices. But in 1918, revolution breaks out and Bredow's plans are ignored. However, his hour comes: in 1921, the government appoints the strong man to the Ministry of Posts and Telecommunications to secure all radio stations. These are difficult times for the people of Berlin—for Kupinkes and her daughter Rosi, the revue dancer, as well as for Sergeant Sterzel, the recruit Hasso...