MUR's operative agent Konstantin Troshin returns from the front after the victory in the Great Patriotic War and learns that the police no longer works. The reason is the conflict with the influential NKVD General of the USSR. But without police Troshin cannot live. He manages to get a district in the disadvantaged area of Moscow - Marya's Grove. Due to personal problems, Troshin is forced to live in a communal apartment here, in Marya's Grove. While in the midst of the criminal environment and having come together closely with its inhabitants, Troshin unravels coldblooded murders, daring raids and ingenious scams. But Troshin's goal are not criminals. He has the task to eradicate the crime itself. Being in the position of the district officer, he gradually becomes an arbitrator, whom people trust to separate good from evil.