The end of the 18th century. The old captain Izmaylov has two sons: the eldest, Denis—legitimate; the younger, Nikita, born to a serf actress. The captain adopted Nikita and petitioned Catherine II so that his younger son would receive a noble title and bear his father’s surname. In 1787 the Russo-Turkish War begins. The old captain dies in battle. Denis and Nikita, after finishing the Kronstadt Naval School, are sent to serve in the Black Sea Fleet and become captains of small brigs—the “Nedotyroga” and the “Astrolabe.” Denis receives a special assignment from command: to find exactly where the Turkish fleet is based on the Rumelian (Balkan) coasts of the Ottoman Empire.
Fate brings the brave scout into the palace of Sultan Selim III himself. The younger brother comes to the rescue—Captain Nikita Izmaylov.