Boris Krylov is a top-class criminologist. In his work, he uses paradoxical and non-obvious methods that help him unravel even the most complex crimes, for which his colleagues call him a modern Sherlock Holmes. Due to a divorce from his wife, a brilliant detective leaves the police and makes a living as a consultant on the set of detective series. But when his father, a famous surgeon, dies in a car accident, and he himself is seriously injured, Krylov begins his own investigation. My instinct tells me that the accident was planned: before his death, his father tried to tell him something. So Boris returns to his profession and gets a job as an expert in the investigative department, which is headed by Major Anna Voskresenskaya. Anna was once a student of Krylov. Now Krylov and Voskresenskaya will have to work together. While solving crimes, the heroes deal with their past and feelings for each other.

The story begins before the Great Patriotic War. Jan and Red Army Captain Yevgeny Kostin love each other. But General Danilov is also in love with the girl. In June 1941, Kostin left for a new place of service. The war begins. Jan's hometown is being captured by the Germans. Kostin is injured, but he overcomes hundreds of miles to find his beloved. And in her city he finds 52only... a grave.