The fairy tale begins in hell, where the book of sins has been lost. During his frantic search, the devil's apprentice Vašek finds a pair of shoes and, overcome by curiosity, decides to try them on. Like everything else associated with hell, these shoes are not ordinary, and Vašek suddenly finds himself in the world of humans. Before he has time to get his bearings, he loses them, and with them the chance to return. The shoes have caught the eye of a village boy named Jiřík, and they have brought him to hell instead. Lucifer is furious, because his realm has never faced such a predicament: an innocent child in hell and an inexperienced devil's apprentice accidentally left in the world...

The joyful celebrations at the royal festivities are suddenly interrupted by a juggler's attempt to kill King Gregory. The astronomer Petr, who saves the king, is accepted into service for his deed. He teaches the beautiful princess Korunka to read the stars, but the monarch is not particularly fond of their budding love due to the young man's lowly origins. Three musicians try to help the two lovers with magic, and when Petr manages to save the king from death a second time, it seems that the astrologer's dream will come true and he will finally win the princess's hand. Instead of the expected reward, however, he is banished...