A rich heiress, Maria Sorokina, goes missing after a quarrel with her husband. Boris Novinsky, head of the police station, entrusts this case to a young detective, yesterday's intern, Alina Novinskaya, his daughter. It turns out that a maniac who strangles and disfigures young women who look like Maria Sorokina operates in the town. The search for Maria brings her husband, Mark, and Alina together. Seven years later, Alina and Mark have a strong family. But one day, Mark goes on a business trip and meets there a woman who looks like his missing wife, Maria, like two peas in a pod. Mark is unable to master the feelings that have overwhelmed him again and leaves Alina for a woman who so frighteningly resembles his late first wife. Meanwhile murders of young women are renewed in the town - a mysterious maniac, already forgotten by everyone, goes hunting again. Alina, abandoned by her husband, returns to the police work and the search for a maniac, which leads her to a shocking discovery.

1944. According to information obtained from a recruited German agent, a major act of sabotage is being planned in the Murmansk port, through which the USSR receives vital military cargo from the allies along the northern route. Counterintelligence officers Sergey Saburov and Elena Soley have a new dangerous mission, to prevent large-scale sabotage in the Murmansk seaport, find and neutralize the enemy.

Year 1944. According to information received from a recruited German agent, the Nazis are planning a major act of sabotage in one of the Arctic ports through which the Soviet Union is supplied with food, goods and material of vital importance from the Allies under the Lend-Lease programme. Heroes Yelena Soley and Sergey Saburov, from the "The Black Sea" series, will have to disrupt the enemy operation and save the port from impending disaster

In a dormitory in 1951 four students prefer pranks to studying.

1953 year. Moscow says goodbye to the leader. In the funeral crowd, Eugene met with Elya. During the long hours spent in the funeral procession, they managed to learn a lot about each other ... But Elia absurdly dies. So Zhenya begins another, adult life ...