A chronicle of life in a small village in the Baikal Region on the eve of World War I and at the time of the October Revolution. The age-old foundations are crumbling, the process of social stratification is underway and, as a result, some people go to defend the revolution, and others - to fight against it. The main hero is the young Cossack Roman Ulybin. At first, this carefree daredevil is preoccupied only with one problem: whether his sweetheart, Dashutka, is to marry him or a merchant’s son, Alyoshka. Roman is killing time fist-fighting with his rival. But little by little, the young man realizes that the world around him has changed, that people are fighting for equality and social justice, and, being a real Cossack, he can’t remain on the sidelines…