Thirty-five-year-old bachelor Jiří Šafránek is a train dispatcher, an amateur actor rehearsing the role of Hamlet, and the proud owner of a 1960 Stadion 22 moped. Because of the blue color of his beloved motorcycle, the police call Jiří the Blue Dragon. Jiří still lives with his mother, who finds it difficult to tolerate his escapades. Like Prince Hamlet, Jiří talks to his father's ghost. In addition, he is always running late and shortens his journey from work to theater rehearsals by taking a footbridge where motorcycles are prohibited. One day, he almost collides with a girl named Adina coming in the opposite direction. This marks the beginning of a relationship that will disrupt not only Jiří's coexistence with his mother, but also the preparations for the premiere of Hamlet itself.

This fairy tale, full of humor and suspense, begins in a small town where preparations are underway for a theatrical performance. The play tells a local legend about enormous riches hidden deep underground. Many long to find them, but those who set out in search of them never return. The play features two sisters, Kačenka and Barborka, as well as Jakub, a musician and Barborka's jealous boyfriend. The theme of the play also attracts the miserly lord of the castle, Bořivoj Hájek z Hájku, who arrives with his brother Ignác, an eccentric inventor and researcher. And somewhere underground, near the real treasure, sit his three ghostly guards, passing the time by inventing all sorts of pastimes, which the Lord of the Underground does not enjoy at all. His patience will run out the moment the bored guards interfere with human destinies, because of a bet on how the love between Jakub and Barbora will turn out.

The sudden death of her daughter pushes a mother to defy the laws of physics when she tries to travel back in time to prevent a fatal car accident.