Ilya lives in Moscow; Nina lives in St. Petersburg. Ilya has a beautiful wife and a daughter; Nina's husband is an artist, and they have a young son. Nina occasionally travels to Moscow to see her partners in the publishing industry. Ilya sometimes comes to St. Petersburg on business. But more often they are in the train between St. Petersburg and Moscow just to see each other. Because they have an affair.

In the center of the plot is a senior investigator named Masha Shvetsova and her male colleagues. The plot is the most vital, but, like in “Streets of Broken Lanterns,” it is seasoned with a fair amount of humor - otherwise, how can the audience (and the heroes) endure countless morgues, identifications and other “cute” charms of the investigative routine?