Underground is a 1941 American war thriller film directed by Vincent Sherman and starring Jeffrey Lynn, Philip Dorn and Kaaren Verne. Focusing on the German Nazi Resistance opposing the Nazis in World War II, Lynn and Dorn play two brothers initially on opposite sides. It was produced and distributed by Warner Bros. Pictures.
Kurt Franken returns from his time at the front, minus an arm but still the fervent, patriotic Nazi that he was when he left. His brother, Eric, is high up in the resistance and regularly broadcasts on a secret radio. They argue, at first, but over time Kurt sees things differently. Eric eventually runs afoul of the Gestapo and is scheduled for execution. As he is led to the guillotine, he hears his brother's voice on loudspeakers positioned through the prison.
The Charles Martin Playhouse radio program presented an adaptation of the film on September 18, 1942. Claude Rains starred in the broadcast.