The story "The Sign of Cain" is a literary accompaniment to the third volume of "The History of the Russian State. From Ivan III to Boris Godunov" by the famous writer and researcher Boris Akunin. The reader will spend only one day in the Moscow kingdom, looking at the world through the eyes of Ivan IV the Terrible himself. With all his personal internal struggle between fear and hatred, still childish complexes and insults, but also with the sovereign's view of the country and the people. Akunin's bold creative experiment will certainly be of interest to readers.