Place: Bohemian ore mountainsTime: 14th century.
After falling in love with the mortal Anna, Hans Heiling plans to leave the underworld empire of Erdgeister to wed her. Ignoring the attempts of his mother the Queen to persuade him to stay, he takes some jewels and a magic book enabling him to retain power over his underworld subjects.
Scene 1
Heiling ascends to the earth to find his would-be bride. Heiling finds Anna and her mother, who encourages Anna to accept the advances of the rich stranger. During a moment alone Anna looks inside his book, which immediately fills her with terror. Heiling burns the book on her demand and reluctantly accompanies Anna to the village festival.
Scene 2
There are many people in the tavern drinking, dancing and singing. Stephan and Niklas are joined by Konrad, who has loved Anna for a long time. Anna and Heiling arrive and Konrad asks to dance with Anna. Heiling objects angrily but Anna ignores him; and reminding him that they are not yet married, walks away with Konrad.
Scene 1
Anna wanders through a forest on her way home. She has realised that she loves Konrad, but she remains Heiling's bride to be. Suddenly the Queen appears and beseeches the girl to release her son, who is not a human being but a prince of the underworld. Anna faints and upon discovering her, Konrad takes Anna home.
Scene 2
Heiling approaches Anna in her house, offering his jewellery to win her over, but it is returned by Anna who now knows of its origin. In a rage, Heiling stabs Konrad before running away.
Scene 1
Heiling returns to Erdgeistern. He summons his former subjects, only to be reminded that without his book he has lost his power. He then finds out that Konrad is not dead, and is to be wed to Anna the next day. In his despair, he throws himself on the ground, and seeing that Heiling has lost so much, his subjects swear fealty to him again. With the news of the wedding in his mind, he returns to the earth to take revenge with his new-found powers.
Scene 2
Konrad and Anna are wed in a forest chapel. Heiling approaches and seizes the hand of Anna, who pleads for mercy. Konrad rushes to help his wife, but his knife shatters as he strikes Heiling. Heiling summons the Erdgeister to destroy all the people, but then the Queen appears. She persuades Heiling to reconcile, and they then return to the underworld.