Ershi's sister, Marussia, a sailor of the Black Sea Squadron, was seduced by Baron von Vogel. Coincidentally, he is assigned to the same ship where he serves the nation. The situation on the ship is tense. The arbitrariness of the officers causes discontent among the sailors. Only the ship's mechanic, Menshevik Avalov, weakly defends the interests of the sailors.

Yunker Olenin, a representative of St. Petersburg's "golden youth," travels to the Caucasus in search of romance. His regiment is stationed in a Cossack village. There he falls in love with the beautiful Marina and even decides to marry her, not yet knowing that she loves the Cossack Lukashka and would never trade him for a lord.