The film is about the Time of Troubles, Russia's struggle for independence led by Dmitry Pozharsky and Kuzma Minin against the Polish Invasion in 1611–1612.

By winter, Roman finds himself at a monastery near Moscow, where he meets Prince Dmitry Pozharsky and, at the request of a servant named Stepan, temporarily takes care of the horses.

The scene then shifts to the Sretensky Gates in Moscow, where the Poles block the passage, even throwing carts with logs into the river.

As some areas attempt to extinguish the fires, Prince Pozharsky leads the peasants to the positions of an old gunsmith and rebel, Fyodor Zotov.

As a result, most of the rebels, including Roman, retreat from the city, while the prince’s wife accompanies her wounded husband in a sleigh to his family estate.

As time passes, the Poles capture Smolensk, the Swedes seize Novgorod, and the Cossacks under Ataman Zarutsky kill Prokopy Lapyunov, leading to the disbandment of the First Volunteer Army.

Meanwhile, Polish King Sigismund Vasa learns of this and consults with the Jesuit de Mallo, who had previously delivered a letter to Orlov.

Under persuasion, Stepan agrees to kill the prince and attempts to do so when Swedish mercenaries arrive at the Second Volunteer Army's camp.

At the same time, the traitors Stepan and Orlov attempt to sneak a group of Poles into Moscow but fall into an ambush set by Prince Pozharsky.

The next morning, a fog temporarily covers Moscow, and the militia’s cavalry crosses the river as the decisive battle begins.

Dissatisfied with waiting, the Cossacks switch sides and join the militia, while Polish garrison soldiers in the Kremlin fire cannons and emerge from the gates with banners and joyful songs.

Pozharsky and Minin devise a plan to defeat the enemy, launching a counterattack led by the militia cavalry, which breaks the Polish formations.