American correspondent Bill Roberts is a thorn in the side of the Nazis, as his paper always scoops the world with the truth about Germany. Gestapo Captain Carl Von Rau means to plug the leak and assigns Karen Hauen, who he attends to wed, to the case. Roberts is obtaining his information for his stories and broadcasts from an elderly stamp collector who, defiantly opposed to the Nazis, sells the "proper" stamps to Roberts, giving him the information. Attracted to Karen, Roberts invites her to his apartment where she learns his secret. The old philatelist is sent to a concentration camp, and then Karen learns that he is her father. She appeals to Roberts for help and he, in loyalty to the old man and now in love with Karen, agrees to help.