After a long absence, surgeon Maxim Mikhailov returns to his hometown to help his mother, who is suspected of having an early stage of Alzheimer’s. He gets a job at a local hospital, and on the very first day faces a serious test to operate a patient with a severe brain trauma. Maximov saves the girl, but when transferred to the nearby regional hospital, she dies under suspicious circumstances. The doctor launches his own investigation and finds out the dark truth behind the young woman’s death. It is the first case in a series of medical and criminal mysteries he is going to solve throughout the series. Maksimov is a talented doctor and a passionate person, but his methods are both outrageous and admirable. He keeps saving people’s lives performing the most challenging surgeries but, as it turns out, not everyone is happy about it.

Yuri Bragin, after a year-long business trip, where he, as part of an investigation team, was investigating a high-profile case, returns to St. Petersburg. When he returns, he learns that the current head of the First Investigation Department of the First Directorate of the State Investigation Department, Vadim Maltsev, is retiring. With a high degree of probability, it is Bragin who will be offered his place. But Yuri is not a careerist and the position of the boss is not the goal of his life. A talented investigator likes to do "live work" more. And now he is again sent on a business trip. This time in one of the cities of the Leningrad region, where two girls were killed with a difference of a week. Here, in a small town, everyone knows each other, and this complicates the search for the criminal.