An unknown criminal informs Dubov by phone that he has kidnapped Diana and will return her in exchange for a gun, which is stored in the police archive. If Denis does not hand over the gun within 24 hours, then Diana will die.
Someone brutally dealt with a local resident Baturin. On suspicion of his murder, the police arrest Yakhontov, on whose clothes the victim's blood was found. To investigate the case, her former colleague and lover Roman comes to the department to Diana from the SK. Diana and Roman are sure that they have caught the killer, but Denis does not agree with them and goes to the crime scene again.
Shvetsov, who was trying to get money for a vacation, is being killed in the city. The criminal takes the laptop with the phone of the deceased. At the same time, the city police have been receiving calls about false mining of buildings in the city center for several days in a row. Dubov assumes that these cases are somehow connected and takes the investigation into his own hands.
While Kolyan is worried about parting with Katya, a policeman from Moscow, Vika, appears, who is interested in Dubov. And Agapov appeals to Diana and Gaidukov with a request to find the director of the company, with whom 23 million rubles disappeared. Denis joins the investigation and at the same time tries to find out why Vika actually came.
Kolyan is worried about the missing Katya, and Dubov is trying to calm him down. Diana and Gaidukov are investigating a new murder: a gynecologist Blokhin was found dead in his apartment. In the pockets of his clothes, Diana finds a note with the name of Kolyan's girlfriend who disappeared.
Diana and Gaidukov discover the corpse of a Turkish citizen in an elite residential complex, and drugs are found next to the body. Gaidukov concludes that this is not a murder, and offers to close the case. Dubov categorically disagrees and decides to find out more about the victim's place of work.
Dubov dreams of his funeral, to which no one comes, since he has no friends. He gets very upset and tries to be as friendly as possible with Diana and Gaidukov, which surprises both of them very much. Meanwhile, the city is shaken by the murder of the owner of the winery, and the investigation comes to a dead end.
A gang appears in the city, which steals expensive paintings. Diana decides to ambush the criminals, but everything does not go according to plan. Dubov learns that his state defense is over and he must return to Moscow.
