Lena's father works as a developer in Hitler's high-tech forge, where the famous unit receiver E1 was developed. When he dies in 1945, he leaves a notebook with the name Sattler. He should look for Lena. Lena is stranded with her seriously ill mother Hilde and her sister Betty in a village near Fürth. Here she meets two men: Walter Juskowiak, returnees from prisoner of war, with whom she meets, and Hans Sattler. The representative for radio kits turns out to be the son of Wilhelm Sattler, owner of the Sattler works in Fürth. Lena is sure to have finally found the right man.
