The company where Polina works receives an order: it is necessary to find out whether there are any illegitimate children in the Vereshchagin family. An unknown person left an inheritance to the men of this family, setting a condition: the lawyers must, at all costs, find all males who can lay claim to a part of it. In order to solve this problem, Polina is forced to go to the wedding of Stas Vereshchagin, which is planned to be held in the castle on the island. The situation is complicated by the fact that Polina is Stas’s ex-girlfriend, abandoned by him for an arranged marriage.