The short novel "The mark of Cain" is a literary accompaniment of the third volume of "History of the Russian State. From Ivan III to Boris Godunov" by the famous writer and researcher Boris Akunin. The reader will spend only a day in Moscovia, looking at the world with the eyes of Ivan IV the Terrible himself. With all his personal inner struggle between fear and hatred, yet childish complexes and resentments, but with a sovereign-like outlook on the country and the nation. A trailblazing experiment of Akunin will be of interest to readers, for sure.