The main character of the story is a handsome, skilled and rich young warlock who saw emotions as a weakness, and decides to take measures to prevent himself from ever falling in love, using the Dark Arts. The Warlock becomes deluded, believing himself to be envied for his "perfect" solitude, which makes him all the more upset to overhear two servants talking about him; one servant is taking pity on him, while the other is ridiculing him for not having found a wife. This swings a blow to the Warlock's pride, and he decides to find a beautiful, magically talented and wealthy young maiden, so that he will be envied by all.[
The next day, he has the fortune of meeting such a woman; though the maiden is both "fascinated and repelled" by the Warlock, he persuades her, along with her family, to come to a dinner feast at his castle. The Warlock attempts to flatter the young woman, using words he steals from a poet. The maiden retorts that she would only believe such lovely words if she thought he had a heart. The Warlock takes her down to the dungeon of his castle and shows her an enchanted crystal casket, within which lies his own beating heart.
Because the heart had been parted from its body for so long, it had become shrivelled and covered in black hair. The maiden asks the Warlock to put his heart back inside his chest, which he does. The woman is so pleased that she runs forwards and embraces him. However, the heart had been consumed by the Dark magic used to remove it, and had degenerated into a savage, bestial state, driving the Warlock to take by force a truly human heart. He tears out the maiden's heart to replace his own, but his own heart is too strong and does not allow him to use magic. Not wanting to be mastered by his heart, he cut his own heart out. Before he could replace his own heart with the maiden's heart, he died across the maiden's dead body with one heart in each hand.