This film continues the story of radio operator Ludwig Bartuschek from “The Sailor’s Song”. Near the end of the Weimar Republic, Bartuschek (Erwin Geschonneck) is working as a mechanic in the Sperber airplane plant. Director Dehringer offers him the opportunity to train as an airplane constructor if he is willing to give up his communist beliefs under oath. Bartuschek will not allow himself to be bought and instead joins the underground resistance movement.