Harry Haller, a middle-aged intellectual, moves into a lodging house in a medium-sized, generic town, which is never named. Despairing and melancholy, Harry feels himself to be “a wolf of the Steppes,” or “Steppenwolf,” adrift and alone in a world that is incomprehensible to him and offers him no joy. Steppenwolf recounts Harry’s pain and anxiety as he tries to overcome his crippling sense of dislocation and despair at the futility of humanity.

Harry is repulsed by the productive, organized, and diligent optimism of the bourgeoisie, or middle class. Even so, he is bewitched by its charms. Caught between the urges of his wolf-half and his man-half, Harry can neither completely disavow nor embrace a conventional way of life. He regularly contemplates committing suicide.

One night, while Harry walks unhappily through an old quarter of the city, he sees a sign over a door he has never noticed before. The sign reads “MAGIC THEATER—ENTRANCE NOT FOR EVERYBODY.” More letters reflected on the street spell out “FOR MADMEN ONLY!” Harry cannot open the door, but a sign-bearer advertising the Magic Theater gives Harry a booklet entitled “Treatise on the Steppenwolf.” This booklet contains a precise description of the way Harry feels as a Steppenwolf. It speaks of a person who is half man and half wolf who hates the bourgeois lifestyle but who is also at the same time incapable of surrendering himself to the pleasure of the senses.

Harry soon becomes even more certain that he must kill himself immediately. At a professor’s house, Harry gravely insults his former colleague about the way Goethe, the famous German poet, is represented in a portrait that hangs in his home. Feeling that he has at last severed all ties to humanity, Harry plans to commit suicide that evening. However, Harry meets an enchanting young girl in a tavern that night, and she gives him sensible and maternal advice. The two meet again the following week. Because the girl resembles a boyhood friend of Harry’s named Herman, Harry guesses that she is called Hermine. He is correct. Hermine begins to help Harry. Grateful that she has broken through his isolation, he agrees to obey all her commands. Hermine informs Harry that eventually she will make him fall in love with her, then she will ask him to kill her.

Hermine teaches Harry to dance, finds him a lover named Maria, and introduces him to an enigmatic and beautiful jazz musician named Pablo. Through Hermine and her friends, Harry begins to immerse himself in a hedonistic, or pleasure-filled, way of life. He comes to appreciate all the sensual aspects of life he had previously disregarded because of his strict bourgeois upbringing. With Hermine and Maria, everything from buying little love gifts to picking duck meat from its bones becomes a delightful affair. Harry blooms and becomes happy during these weeks of change. Despite the enjoyment he feels, however, part of him remains repulsed by his transformation. Part of Harry continues to aspire toward the spiritual and the divine, away from the sordid pleasures of the flesh. When Harry confesses his feelings, he finds that Hermine understands him perfectly. In fact, she understands him better than he understands himself.

Harry’s concerns peak at the Fancy Dress Ball, a gala masquerade dance Harry attends. After several hours of liberating, riotous revelry, Harry consummates his love with Hermine through a nuptial dance. As the ball comes to a close, Pablo invites Harry and Hermine to enjoy his Magic Theater. Pablo explains to Harry that the goal of the theater is the dissolution of the personality, a goal that can be accomplished only through laughter.

Once inside this “school of humor,” Harry laughs at a mirror image of himself and goes down a corridor lined with dozens of strange doors, some of which he enters. Each door opens on a new, surreal world. Harry runs from one world, in which men and machines are engrossed in a bloody war, to another, where all the women he has ever wanted are available for him to enjoy.

Reality quickly falls away as the novel brings us deeper and deeper into the psyche of the Steppenwolf. Harry ends up in a room where he finds Hermine and Pablo’s love-spent, naked bodies lying on the floor. Believing that the moment has come to fulfill his promise to kill Hermine, Harry stabs her with a knife that has magically appeared in his pocket. The celebrated classical composer Mozart appears and tells Harry that he has abused the Magic Theater with such excessively serious behavior. Mozart explains that life is always compromised and full of less-than-ideal circumstances, and that the task Harry must face now is to greet these aspects with laughter. Although Harry has failed this time, according to Pablo, he leaves the theater with the deep belief that one day he will get things right.