Conrad Veidt plays identical twins reunited after 8 years apart. One brother, Otto Becker, is an innocent bookstore owner and stamp collector. The other, Baron Hugo Von Detner, is a Nazi official forcing his brother to cooperate in a cover up. The Baron must keep his brother quiet until something happens to keep the Baron quiet. Otto must disguise himself and try to work against the Nazi schemes his brother worked with.
The scenes with the bird who sings for only one brother felt important in the beginning. Later the bird comes back into the story to add more suspense. Even the stamp collecting played an important role in the story. The scene with people booing at someone at the end of the story probably hit a nerve in theaters when this came out in 1942.
Conrad Veidt performed well in this film which released in March 1942, and then he performed the role of Major Heinrich Strasser in Casablanca which released in January of 1943.