The biographical film about the prematurely deceased violin virtuoso Josef Slavík takes place entirely like a haunting dream, in the mind of a feverish artist who remembers how he amazed Paganini himself with his playing.

While in Bohemia, an American industrialist named Craigs goes missing. In Prague, the police have arrested a man without identification, who bears a striking resemblance to Craigs. The doctor, the secretary, and the hotel staff all claim that he is the industrialist. The man denies this claim. When he learns how harsh and despotic the man he is believed to be is, he agrees to go to London and adopts his new identity.

One of the few European films of the 30s to criticize the Nazis, even if they couldn't be directly named due to censorship: Gangsters with gray hats stir up trouble in what is obviously the Sudetenland.