Title romanized.

The heroes of the story - the fragile young violinist Olenka and her friends - Anton, Sashko and Serhiy, accidentally learn about the secret of the hidden jewels of the famous Milady, the heroine of the novel about the three musketeers, while resting in a camp on the shore of the Black Sea. At night, friends secretly go in search of treasure, but fall into a whirlwind of exciting adventures. They will have to make a dangerous journey into the smugglers' cave, as well as engage in a real duel with the thieves of museum values. Who will win in the eternal duel between evil and good - treachery and hatred, or sincerity and friendship?