Events find the heroes on the eve of the Great Patriotic War. Irina is the wife of a high-ranking man and the daughter of an enemy of the people. She teaches German at Moscow State University, and NKVD Major Pavel Nechai turns to her as a specialist in the ancient Germanic epic. He asks Irina for help in finding a rare German book, the text of which is used for enemy encryption.
There is a sabotage group operating in the city, and Irina finds herself drawn into a large-scale spy story. Her husband and her childhood friend Andrei Galkin, with whom she was passionately in love in her youth, suddenly returned to her life, also find themselves in the field of view of the People's Commissariat of Internal Affairs.