His Evenk friend shot dead by the corrupt politician's thuggish supporters, an eighteen year-old Cossack saddles the recently deceased's pony-sized steed and prepares to make the 4,000 mile trip to St. Petersburg in hopes of ensuring that the czar fulfills his promise to protect the indigenous population of Siberia. The year is 1889, and the malevolent followers of a corrupt governor have offered to trade guns and flour to the Evenks for a special herd of horses. When teenage Cossack Dimitri Pechkov (Aleksei Chadov) sees murderous henchman Bouvarine (Nikolai Smirnov) gun down his Evenk acquaintance, he soon makes it his mission to ensure that no further harm comes to the peaceful tribe. Despite the fact that Dimitri has never ventured beyond the borders of the small village in which he was born, his drive to earn the respect of his distant father prompts the brave youngster to rechristen his fallen friend's horse Serko and brink the matter to the czar's attention. Over the course of the next 193 days, Dimitri finds his noble quest growing increasingly arduous as the fearful governor sets out to insure that his message never reaches the powerful monarch.