Acting couple Joseph (Jack Benny) and Maria Tura (Carole Lombard) are managing a theatrical troupe when the Nazis invade Poland. Maria is having an affair with Lieutenant Sobinski (Robert Stack), who suspects Professor Siletsky (Stanley Ridges) is a Nazi spy. With Siletsky in possession of a list of members of the Polish resistance, the Turas' company takes action. Using their skill for impersonation, Joseph and company must confuse the Nazis and stop Siletsky from handing over the list.