The novel opens with a preface allegedly written by the nephew. In this he tells us how he hcame to meet Harry Haller, or Steppenwolf, when Harry rented a room in the boarding house owned by his aunt. He tells us that he did not at first like Steppenwolf, but came to like him over time. At first the nephew thought Steppenwolf to be snobbish, and unsociable.
But he comes to see him as a sympathetic character, the “genius of suffering,” is what he calls him. He tells us that he is going to relate the story of Steppenwolf without any commentary, even though he continually offers psychological observations. Steppenwolf, however, leaves behind a manuscript which the nephew publishes. This is the story, or “Harry Haller’s Records.”
With the exception of the treatise section, the rest of the novel is narrated by Steppenwolf. He describes his disgust of bourgeois society, but also says that he is fascinated by it. He lives among the bourgeoisie even as he hates them. An example is his room he rents from the aunt. He has rented many other rooms from people just like her in the past.
His daily life is dull. He describes himself as an old man in his fifties. He spends the day consumed by routine, reading the newspapers and books. He is generally discontent with society and what he sees as his own divided nature compel him to consider killing himself. At some point, though, he sees a sign which reads: “MAGIC THEATER. ENTRANCE NOT FOR EVERYONE. FOR MADMEN ONLY.” With this, a peddler offers him the pamphlet called “Treatise on Steppenwolf.”
The treatise would seem to describe Harry Haller perfectly. It explains that he consists of two natures. He is dominated by the human and the wolf. The human side requires order and responsibility. These are the bourgeois values Harry despises.
The other side, the wolf, desires physical pleasure and gratification. Where this comes from is of no importance, he cannot resolve these two natures and thus he lives in a state of constant turmoil. Steppenwolf, the treatise explains, rarely experiences a moment of peace and generally feels isolated.
The treatise continues to explain that there are many Steppenwolves in the world. Every individual consists of multiple selves. Since society generally does not accept the idea of multiple selves, Steppenwolves are destined to be isolated in society. They are often rejected and suicidal. However, the treatise explains that suicide is not the answer.
Steppenwolf considers what the treatise says in relation to a poem he had already written about himself. After considering everything, he decides to commit suicide. Later, he runs into an old acquaintance, known as the professor, who invites him to dinner. Steppenwolf accepts the invitation with some trepidation.
While at the professor’s house, Steppenwolf sees a portrait of Goethe which he finds repulsive. In the course of conversation, the professor mentions that he read an article about a traitor named Harry Haller. Steppenwolf admits that this is he, and leaves the professor’s home. He decides to kill himself. But when he arrives home, he realizes he is afraid of death and more afraid of killing himself.
Steppenwolf visits a character named Black Eagle and meets a woman sitting at a table. She makes him eat and get some sleep. As he sleeps, he has a dream that included Goethe, a black scorpion, and a woman’s leg in a box. In the dream, Goethe tells Steppenwolf that he is taking life too seriously.
After he wakes, the woman says she is leaving. She accepts a dinner invitation from Steppenwolf. As she leaves, she tells him that she understands why does not like the picture of Goethe. She says she does not like pictures of saints.
Steppenwolf does meet with the young woman. He manages to guess her name: Hermine. She tells Steppenwolf that he will eventually fall in love with her, and she will tell him to kill her. The two talk about the newspaper article referring to him as a traitor. They discuss the possibility of another war. Hermine buys a gramophone and teaches him to dance. Later, Steppenwolf sees Maria for the first time, and he is able to dance with her.
Hermine tells Steppenwolf that she is impressed with his dancing skills. She tells him he needs to have sex with a young woman, which Steppenwolf resists because of his age. Hermine dismisses this objection. Later, he talks about music with a musician named Pablo and attends a recital.
When Steppenwolf returns home, he finds Maria in bed. The two engage in a sexual relationship for the next three weeks. This culminates in the Fancy Dress Ball. Steppenwolf is troubled by the fact that he is not Maria’s only lover, but at the same time, he is thankful for her attention and to Hermine for arranging things.
Steppenwolf tunrs down an invitation from Pablo for he and Maria to participate in an orgy. Pablo also tells Steppenwolf that he and Maria are lovers. Steppenwolf also finds out the Hermine and Maria discuss all of their sexual experiences with each other. At this point, Hermine reminds Steppenwolf that they will one day be lovers.
Hermine tells Steppenwolf that she became a prostitute because her life came up short of her expectations just like his. She had great dreams and aspirations, but she ended up where she is anyway. Steppenwolf tells Hermine that he is happy being with Maria, but he knows it is temporary. He tells her that only death awaits him. Hermine tells him that death and eternity are all that are left for her.
On his way to the Fancy Ball, Steppenwolf stops in a theater to watch The Ten Commandments. He later arrives at the ball and looks for Hermine. As he is about to leave, he is handed a ticket which says “TONIGHT AT THE MAGIC THREATER. FOR MADMEN ONLY. PRICE OF ADMITTANCE YOUR MIND. NOT FOR EVERYBODY. HERMINE IS HELL.”
Steppenwolf eventually finds Hermine. She is dressed like his childhood friend, Herman. Both of them dance with other women. Hermine later appears dressed as a dancer. As the ball comes to an end, Pablo invites Steppenwolf into his magic theater. Steppenwolf sees several galleries. He watches his life before him, and reviews and edits it as it unfolds.
His two natures appear and fight for dominance. He sees his wolf nature murder people and kill Hermine. A magic knife appears in his hand and he tries to kill Hermine. Mozart appears and tells him that he has behaved badly in the Magic Theater. He explains that life is filled with not ideal and we must face compromise and disappointment with laughter.
Mozart admonishes him for his elitist bourgeois attitudes. He tells Steppenwolf that he is no different from the people he hates and he is ultimately responsible for the things he has done wrong. Finally, Pablo appears to tell Steppenwolf that he did not actually kill Hermine.