The film is based on three works by Yulian Semyonov: the short story "Tenderness" and the novels "Diamonds for the Dictatorship of the Proletariat" and "No Password Needed." In the first novel, Isaev successfully solves the case of theft from Gokhran during the difficult 1920s, while the second tells the story of a young intelligence officer's infiltration into the White Guard movement in the Far Eastern Republic.
