Andrei Prokhorov is terminally ill. Therefore, seizing on the only chance, he agrees to participate in an experiment on the transfer of consciousness. And, having prepared himself, he goes back in time. In 1552, he found himself near Tula in the body of a 14-year-old boy, Andreika, the son of a small local nobleman. There is almost no money. The estate was ruined and deserted by the Tatars. And a year later, he will be recruited for service, to which he must go “on horseback and in arms”... Will Andreika cope? Will he be able to survive and settle down in a new, inhospitable world?