Harry Haller is a lonely, suicidal intellectual approaching age 50 who has become an outsider in society through self-isolation. He has lost his job, his wife, and his home, and along with these his happiness and hopes for a better future. Though he was once a thriving part of the bourgeois world around him, Haller now despises it and finds life without meaning. Haller hides away in his room drinking wine, reading books, and wallowing in self-pity. Haller views himself as having two personalities, the man the world sees and a wild wolf (the "Steppenwolf") that rages inside him. Haller blames his wolf side for his unhappiness and poor social skills, but he cannot see his true nature. In truth he has countless personalities, and by suppressing them he prevents himself from enjoying life and truly knowing himself. Haller longs to be one of the immortals, geniuses who exist in a divine state of consciousness, and at times he gets a taste of this bliss himself. By opening the door to new possibilities, Haller begins to make progress in this direction. Haller allows the vibrant Hermine to immerse him into the jazz club culture, far outside his comfort zone. Here he meets Maria and Pablo, both of whom teach him valuable lessons in self-discovery. When Haller at last has the experience and courage needed to enter the Magic Theater, he is able to let go of the Steppenwolf and open the way for other sides of his personality to emerge.
Hermine is a sassy prostitute with the charming bossy streak of a mother hen. Like Haller, she suffers from disillusionment with life. She is an intelligent woman who thinks and feels deeply and who is cut out for more than her station in life allows. Rather than submitting to a mind-numbing job, a marriage of convenience, or growing old in poverty, Hermine has become a courtesan, or high-class prostitute. She uses her looks and charm to get by in life, and gets her kicks where she can, most often in the clubs, where she delights in dancing. Hermine seems to understand Haller better than he understands himself, and she continually pushes him to try new experiences beyond his comfort zone—to live a little and have some fun. Under her tutelage Haller learns to dance and enjoy jazz, takes Maria as a lover, and gains entrance to the Magic Theater. It is Hermine who introduces Haller to both Maria and Pablo, who figure prominently in his personal transformation. In the Magic Theater Hermine is reduced to but one piece of the game of Haller's life, though a hint is given that her piece may be played again. (At Haller's "execution" Mozart suggests Hermine might be restored to life so Haller can marry her.) In essence though, Hermine is simply one facet of Haller's personality coming out as he explores his own nature.
Pablo is a passionate saxophonist who dabbles in drugs, enjoys the favors of both women and men, and lives for making music. At first Haller isn't terribly impressed with the laid-back foreigner, who won't engage in intellectual debates with him over music. Later Haller comes to understand it is not the theory of music but its live performance that truly drives Pablo. As the leader of the band, Pablo creates a jazz experience that uplifts dancers into an ecstatic state of joyful movement and sound, allowing them to forget that anything else in life exists beyond the present moment. Haller later discovers Pablo is among the immortals, for it is Pablo who invites him into the Magic Theater and who helps him pick up the pieces afterward. Pablo's interest in Haller is in helping him attain that immortal level of consciousness: to learn to laugh and enjoy a life that is often brutal and mirthless. Pablo is kind to Haller, even when admonishing him about mucking up his first visit to the Magic Theater. "You will do better next time," he reassures Haller, even as he pockets the tiny figure of the "dead" Hermine. Pablo is a reliable, enlightened guide who gently challenges Haller to explore his personality at his own pace.
Maria is an affable young woman who loves dancing and above all thrives on love. Her purpose in life is to seek as much sensory pleasure as possible. Her ecstatic love of jazz even moves Haller to a greater appreciation of the music. Maria is kind to Haller and encourages him to enjoy the pleasures of life, and she's not too shy to make the first move. She accepts Haller isn't the life of the party and has empathy for his troubles. Haller isn't her only lover, though, and she doesn't always have time for him. Maria can be seen as a goddess of love, offering Haller (and others) the experience of a giving, unselfish love. She enjoys pleasing him just as she enjoys the pleasures of music and dancing. Maria's love helps Haller see how deeply his wife wounded him, which helps this wound further heal. Her love lifts him into "radiance" for the first time since his divorce, and he sees himself again as a divine being through this encounter. Maria is also remarkable in Haller's life in that she is the first nonintellectual woman he has loved.
The narrator is a thoroughly ordinary, respectable bourgeois man. He goes to work and comes home punctually to his aunt's boarding house, and he abstains from vices such as alcohol. The narrator, whose name is never given, seems both sensible and trustworthy, and since he chooses to publish Harry Haller's Records, he seems to endorse them as both real and worthy of attention. While he is at first suspicious of Haller, who seems "alien," over time he develops a sympathetic rapport with him. The strange man intrigues him, even causing him to snoop through Haller's room, and this curiosity does not evaporate after Haller disappears. He admits he still wonders what Haller is doing, and he imagines Haller living a similar life somewhere else. Haller has opened the door to a new world for the narrator, offering him a glimpse of life outside the narrow confines of the bourgeoisie. It is not impossible to suppose the narrator just might follow in Haller's footsteps and go off in search of the Magic Theater himself.