Swan Lake is the most famous ballet in the world. It is this production that the street dog Samson has to save. One day,in Moscow at the beginning of the 20th century, while hiding from stray dog catchers, he ends up in a famous theater, where he meets the favorite of prima ballerina Anastasia, the dog Margot. And it was at this moment that a unique tiara that belonged to Catherine the Great, which Anastasia would have worn in the fourth act of the ballet, disappears from the dressing room. The performance is in jeopardy! Margot and Samson have to find the jewel thief and save the performance.