The action of the film takes place in the post-war years, when a particularly dangerous gang of criminals "Black Mask" operated on the territory of Yakutia under the leadership of a former circus performer, strongman Ivan. Another strongman, senior police lieutenant Gavril Desyatkin, was ordered to neutralize the criminals. The film is based on the novel of the same name by the famous Yakut writer Egor Neimokhov and is based on real events that took place in Yakutia.