The book is the first part of a duology. The book is written in the genre of fantasy, in the subgenre of alternative history. After the death of the autocrat Ivan the Terrible, his consciousness is transferred to the young Prince of Vladimir Yuri Vsevolodovich in 1212, 24 years before the Mongol invasion. Ivan, in the body of Yuri, begins to actively prepare Rus' to repel the Mongols. Using the knowledge and political experience of Ivan the Terrible, Yuri exterminates the appanage Rurik princes and limits the autocracy of the boyars. Conducts government reform and reorganizes the army. Creates powerful artillery. Conquers appanage principalities one after another. By 1226, he completely united Rus'. Conquers and annexes to Rus' the lands of the Mordovians, Estonians, Lithuanians, Livonia and Prussia. Concludes an alliance with Bulgaria, Poland and Hungary. Defeats Subedei's Mongols. In 1228, he drives the crusaders out of Constantinople and is crowned Tsar of Russia.