The story of a starving author called Geoffrey Tempest who receives some letters. One from a friend who offers to introduce him to a friend who might be able to lift him from poverty. Another from a solicitor detailing that he has inherited a fortune from a deceased relative. The third is a letter of introduction from an aristocrat called Lucio, who befriends him and proceeds guide him in how to use his wealth. Lucio is the earthly incarnation of the Devil. Over the course of the book, Tempest's wealth leads to misery. Eventually, when confronted with the true nature of his companion, he renounces evil and returns to society penniless but content with the chance to purify his soul.