Autumn 1237... The Russian land froze in alarm - a huge horde of Batu is gathering in the steppe near the upper reaches of the Voronezh River. The prince of Ryazan, Yuri Ingvarevich, is also saving up on the border, he sends messengers for help to Vladimir and Chernigov. Soon his army will enter into a bloody section in order to die with honor, Ryazan itself will soon turn to ashes... The help of neighbors - the principalities of ancient Russia will disappear separately... But one morning our contemporary will wake up in the body of the young warrior Yegor from the foreign Yelets. History student, amateur reenactor - can he change the course of history and prevent tragedy in the remaining few weeks before the invasion? Or will he become one of the grains of sand that the Mongol horde will sweep away on its way?!