Immediately after the October revolution, in Russia, stir unrest and propaganda against the Government of the United States. Bela Lugosi is Serge Oumansky, Communist agent trying to organize terrorist actions against the same United States.—Charles Neighbors

Margaret Smith leads a double life: during the week she is "Sonia," a Russian cafe dancer, and on Sundays she returns to her house in the suburbs, where she is known as "Miss Smith." Dick Foster, the son of a millionaire, is infatuated with "Sonia"; Bob Smith, Margaret's brother, is employed by the elder Foster and is weak enough to embezzle $10,000 from him. Margaret goes to old man Foster and begs him to be lenient with Bob; when he refuses, she returns as "Sonia" and makes a deal with him: she will disillusion Foster's son if he will let her brother go. Margaret is later responsible for the wholesale arrest of a gang of Red agents by the Secret Service. She then reveals her deception to the Fosters, and she and Dick decide to be married.—AFI