September, 1941. In a turn of events, young lovebirds Kostya and Nastya find themselves on board a barge that will evacuate people from the sieged Leningrad. At night the barge gets into the storm. When it starts sinking, enemy planes — but not rescuers — were the first to arrive at the scene.

Saving Leningrad

In one of the ordinary Moscow schools, a gifted chemistry teacher, Igor Sarochkin, works honestly. As a result of several years of hard work, he manages to invent a unique substance, thanks to which it is possible to determine the fate of a person and his innate inclinations towards noble deeds or criminal acts. American intelligence services send to the scientist his former classmate Vorofeev, who has lived in the United States for a long time and works for the CIA. The traitor manages to steal a sample of the substance from Sarochkin's laboratory. However, no one will be able to use the sample without the secret formula that the chemist keeps in his head. To protect the brilliant scientist and give him the opportunity to implement his project, the FSB general develops a cunning plan. FSB Major Darya Timofeeva will have to get closer to Igor, using the legend of the scientist's first love, whom he has not seen for seventeen years.