Vathek tells the story of Caliph Vathek, a man who renounced religion and instead became involved with a number of dishonorable supernatural events. At the beginning of the text, Vathek is a civil and religious leader and is depicted as being impressive but also hedonistic and immoral. For example, he bribes a number of scholars and builds himself five palaces for his own indulgence.
One day, a repulsive and hideous stranger enters the kingdom and offers Vathek some sabers containing letters the Caliph is unable to read. Strangely, Vathek notices that the inscriptions on the sabers change daily. In desperation, Vathek invites the hideous stranger back to the palace in order to translate the inscriptions and finds out that a sacrifice is necessary.
In response, Vathek cruelly sacrifices fifty children in the kingdom, which causes uproar and anger. On another mysterious parchment, Vathek is told to find the mountains of Istakhar, where secrets of a dark world will be made known to him. While traveling there, they meet messengers of Prince Emir Fakreddin, and his beautiful daughter Nouronihar. After discovering she is already betrothed, Vathek resolves to marry Nouronihar by force, but Fakreddin finds out about the plot and puts an end to it by pretending Nouronihar has died.
Vathek believes Fakreddin's trick, but Nouronihar is discovered alive and Vathek finds her. She becomes one of his wives and soon supports Vathek on his quest to discover the dark world. Finally, they arrive at the mountains and discover Eblis, the lord of darkness. Here, they find wealth, curiosities, and strange creatures. Carathis, Vathek's evil mother, is also summoned to Eblis' palace. However, when she arrives her heart catches on fire as a punishment for her crimes. Then, Vathek and Nouronihar experience the same punishment, and moral order is restored.
