The film is set in the 1920s. It tells about Isaev's first assignments. First, he goes to the capital of bourgeois Estonia, Revel (now Tallinn), to stop the smuggling of valuables stolen from Gokhran. Upon his return, Felix Dzerzhinsky sends him to Vladivostok to collect information about the actions of the White Guards. Then he has to go abroad to observe the counter-revolutionary emigration. Part one - "Diamonds for the dictatorship of the proletariat" (8 episodes). Part two - "No password needed" (8 episodes). The plot is based on three works by Yulian Semyonov from the cycle about the intelligence agent Maxim Maksimovich Isaev: the novels "Diamonds for the Dictatorship of the Proletariat", "No Password" and the story "Tenderness".—zoroman2008