Concern is a fantastic novel by Konstantin Kalbazov, the first book of the Rosich cycle, a genre of historical fiction, and Popatans. Three friends are transferred by chance from 1998 to 1898. What should they do? Remain just outside observers, concerned only with their well-being? Or intervene in the course of history and try to win the upcoming Russo-Japanese war? The question is serious. The answer is ambiguous.