The opera opens in a tavern, where a village celebration is taking place. Music is playing and everybody is dancing, but Jirka, the shepherd, has to go to work, or his master would fire him. Before he leaves, Kate and her mother turn up. Kate would like to find a husband, but nobody wants to dance with her, because she's cheeky and sharp-tongued. She says that she would marry even a devil. At that moment, the devil Marbuel enters the tavern, disguised as a huntsman. He had been sent by the lord of hell Lucifer to investigate whether the princess and steward have committed enough sins to be taken to hell. He wants to tease Kate and punish her a little for her sharp tongue, so he asks her to dance and proposes her to leave with him. When she agrees, he takes her to hell. Then Jirka returns, saying that his master had sent him to hell. When he hears what happened, he decides to save Kate.