The novel tells the story of Felix Canaris, a brilliant and ambitious young writer, and Jasper Helwyze, a wealthy and enigmatic man who becomes a mentor to Felix. The novel is a retelling of the Faust legend, with Jasper Helwyze playing the role of Mephistopheles, the devil's advocate.

Felix is struggling to find success as a writer and is willing to make a Faustian bargain to achieve fame and fortune. He encounters Jasper, who offers him wealth, power, and the opportunity to realize his ambitions in exchange for his soul. Felix agrees to the deal, and Jasper becomes his benefactor, providing him with the means to achieve literary success.

As Felix rises to fame and fortune, he becomes increasingly corrupt, abandoning his principles and moral values. His association with Jasper leads to a series of moral and ethical dilemmas, and he begins to question the cost of his Faustian bargain.

Throughout the novel, the characters grapple with themes of ambition, temptation, moral decay, and the consequences of making a pact with the devil. The narrative explores the darker aspects of human nature and the choices individuals make in pursuit of their desires.