Brilliant journalist Kira Urusova is concerned about the disappearance of her younger sister. Nastya has been married to the head of a large metallurgical concern Andrey Lopatin for several years, but Kira was initially against this marriage: Lopatin is much older than Nastya, and his ex-wife disappeared under unclear circumstances. Kira and Andrey find out that Nastya went to the island of Salty Mane to a certain Source, which became an object of pilgrimage, in the hope that it will help her get pregnant. After which she stopped communicating. Once on the island, Kira and Lopatin begin their own investigation. During the search, they become close and realize that they are in love with each other. Suddenly, a task force comes from the mainland to pick up Lopatin - he is detained on suspicion of murdering Nastya. Kira does not believe in the guilt of the man whom she has fallen in love with. But in order for others to believe it, she needs to complete the investigation and find her sister.