The group detains librarian Dmitry Laval, but they lack direct evidence.

While Dobrovolskaya and one of the teenagers are imprisoned in Fischer's basement, Bokov and Kozyrev go after the killer.

1992. Three children go to the slot machine club and do not return home. Bokov, Kozyrev and Dobrovolskaya will have to face the Fischer case again.

The mystery of Igor Maltsev has been solved, the Fischer case continues to destroy the lives of its leading investigators, and another tragedy occurs at a stable near Moscow.

The main suspect escapes from the investigators, and another child disappears in the area.

Tensions in Kurortnoye have reached a boiling point: residents are outraged and demand the town be made safe. Nadezhda Raykina is torn between the investigation, her pregnant younger sister’s wedding, and her feud with the mayor. Forensic expert Varya organizes a search operation, Zlobin continues interrogating Slava Vdovin, and Bokov looks for evidence against the new suspect. Meanwhile in a Moscow prison, the maniac Sergey Golovkin confesses why he killed people.

Yevgeny Bokov suspects a mass killing took place in the mansion, but the mayor presents the tragedy as an accident. During interrogation, Ostrovsky reveals compromising facts from Slava Vdovin’s past, and the fleeing young man is declared wanted. Meanwhile Zlobin finds the ritual shop where the black ribbon was purchased, and the investigation gets a new witness — a surviving victim of the serial killer.

After the tragic night, the police organize a search for the missing mother and her older daughter, and seasoned investigator Yevgeny Bokov helps his young colleague cope with the stress. Meanwhile, on the shore of the Black Sea, visitors from Moscow discuss an illegal deal and anticipate pulling off a big score. The resort town becomes unsafe, and the mayor gives Nadezhda Raykina a hard ultimatum — find the criminal within 48 hours.

After meeting with a psychic, the investigators pick up new leads, and Bokov gets a tip where to find Slava Vdovin. Meanwhile Valery Kozyrev arrives in Kurortnoye and his presence completely changes the situation in town. Nadezhda Raykina continues fighting to adopt Masha Yershova and is preparing for her younger sister’s wedding, which is tomorrow. After a long day at work, Yevgeny Bokov invites Lyuba to a double date at a restaurant with Vanya and his wife.

1986, Moscow region. A mutilated body of a child is found in the area of government dachas. Three investigators take on a case that will change each of them forever.