The novel is presented by Harry Haller’s notes, found in the room where he had lived and published by the nephew of the hostess of the house where he rented a room. On behalf of the nephew of the hostess the preface and notes are written. There Haller's life is described and his psychological portrait is given. He lived very quietly, looked like a stranger among people, both wild and timid, in a word, he seemed a creature from another world, and called himself the Steppenwolf, lost in the wilds of civilization and philistinism. First, the narrator refers to him wary, even hostile, as if feels in Haller a very unusual man, very different from all others. Over time caution is replaced by sympathy, based on the large sympathy for the suffering person who failed to reveal the richness of his forces in the world, where everything is based on the suppression of the will of the individual.
Haller is a scribe by nature, far removed from the practical interests. He never works, stays in bed for long, often gets up almost at noon and spends time among books. The vast number are the works of writers of all time from Goethe to Dostoevsky. Sometimes he paints watercolors, but always one way or another is in his own world, not wanting to have anything to do with the surrounding philistinism safely having survived the First World War. As he Haller, the narrator, too, calls him Steppenwolf, wandered in the city, in the gregarious life, no other word can describe his shy loneliness, his savagery, his anxiety, his homesickness and rootless. The character feels two natures within him - human and wolf, but in contrast to other people, who had pacified a beast in them, his man and wolf did not get along, did not help each other, but always stayed in a deadly feud, and one tormented another, and when two sworn enemies converge in one soul and in one blood, life is no good.
Harry Haller tries to find a common language with people, but fails, even when dealing with those like himself - intellectuals who are the same as all respectable philistines. Having met on the street a professor he knew and at his home, he can not stand the spirit of the intellectual middle class, which the whole situation is impregnated with, starting with a groomed portrait of Goethe, who is able to decorate any philistine house, and ending with host’s arguments about the Kaiser. Enraged hero wandering around the city realizes that this episode was a farewell to the middle-class, moral, scientists, it was a victory of Steppenwolf for him in his mind. He wants to leave this world, but is afraid of death. He accidentally wanders into the restaurant "Black Eagle", where he meets a girl named Hermine. They start kind of an affair, but it is rather a relationship of two lonely souls. Hermine, a person more practical, helps Harry to adapt to life, attaching him to the night cafes and restaurants, to jazz and her friends. All this helps him even more clearly to understand their dependence on bourgeois, deceitful nature: he stands for reason and humanity, protests against the cruelty of war, but during the war he did not let himself be shot, and was able to adapt to the situation, found a compromise. He is the enemy of power and operation, but in the bank he has a lot of shares of industrial enterprises, on the interest from which he lives shamelessly.
Reflecting on the role of classical music, Haller sees in his reverence for it the fate of the entire German intelligence: instead of experiencing life, a German intellectual dreams of a language without words, the ability to express the inexpressible, wants to go to the world of marvelous and blissful sounds and moods that never are put into reality, and as a result - the German mind has missed most of his original tasks. Validity is determined by generals and industrialists considering intellectuals to be unnecessary, detached from reality, irresponsible witty talkers. In these reflections of both the hero and the narrator, apparently, lies the answer to many questions of German reality and, in particular, the question of why one of the most cultured nations in the world has unleashed two world wars that have almost destroyed humanity.
At the end of the novel he goes to a masquerade ball, where immerses in the element of eroticism and jazz. Looking for Hermine dressed like a young man, Harry falls to the basement of the restaurant – the hell where play the devil-musicians. The atmosphere reminds him of the Walpurgis Night masquerade in Goethe's "Faust" (devil’s masks, wizards, time of day - midnight) and Hoffman’s fabulous visions, where good and evil, sin and virtue are indistinguishable. Running from the world the hero of the German romantic tradition shows a split personality: a philosopher, a dreamer and a lover of music coexists with the killer within him. This occurs in the "magic theater" ( "Entrance only for crazy"), where Haller gets with the help Hermine’s friend saxophonist Pablo, a connoisseur of narcotic herbs. Fiction and reality merge. Haller kills Hermine, meets the great Mozart, who reveals to him the meaning of life - it should not be taken too seriously. Humor is needed in this world – it should help out of desperation, to maintain sanity and faith in man. Then Mozart turns to Pablo, who convinces the hero that life is identical to the game, the rules of which must be strictly observed. The hero is comforted by the fact that one day he will be able to play again.
