An animal trainer steps to the footlights and introduces the main attractions of his circus, among them, Lulu, in the guise of a snake, and then exhorts the audience to wait and see what happens.

Lulu, since the age of thirteen the mistress of Dr. Schön, was married by him to an elderly medical specialist, Dr. Goll. While sitting for her portrait, which is being done by a little-known painter to whom her husband has brought her, she converses with Dr. Schön and his son, Alwa. After father and son leave, the young painter, fascinated by her beauty, tries to approach her. Upon his return, Dr. Goll, enraged by the locked door, breaks it open. In his jealous fury, he suffers a stroke and dies.

Lulu becomes the wife of the painter, by arrangement of Dr. Schön although still maintaining her former liaison with him. Schön manages to secure important commissions for the painter who believes them to be evidence of his personal artistic success. Lulu is visited by Schigolch, an old panderer with whom she spent her childhood. He comes asking for money but slips away upon the arrival of Dr. Schön. Dr. Schön wishes to disencumber himself of his relationship with Lulu because of his plans to marry a young, aristocratic socialite. In the heated words that follow, the painter comes into the room and Lulu leaves. Schön tells the painter of Lulu’s past and reveals the nature of Lulu’s relationship with him. In his despair, the painter commits suicide.

Alwa, who has written a revue in which Lulu appears as the featured dancer, is sitting in the dressing room while Lulu prepares herself for the performance. During her dance, Lulu sees Dr. Schön in the audience with his fiancée and simulates a fainting spell. When Dr. Schön hurries backstage, Lulu threatens to leave him and go to Africa with The Prince, one of her admirers. Realizing that he would never see her again, Dr. Schön submits to Lulu’s dictation of a farewell letter to his fiancée.

The marriage of Lulu and Dr. Schön is developing towards a crisis. Strange persons meet at the house, with and without the knowledge of Dr. Schön: the Countess Geschwitz, a woman deeply in love with Lulu; Schigolch, Lulu’s old friend; his questionable companion, Rodrigo, an acrobat; and a young student who is enraptured at the thought of his first meeting with Lulu. Dr. Schön, driven to the point of insanity by his suspicions, conceals himself in the room. Under his very eyes, his son Alwa declares his love for Lulu. In a rage of madness, Schön gives Lulu a revolver with which to kill herself. As he tries to force it against her, she fires five shots into his body.

Lulu, sentenced to ten years in prison for the murder of Dr. Schön, has contracted cholera. Geschwitz, Alwa and Rodrigo discuss a plan to rescue her from the prison hospital: Geschwitz will take her place and Lulu will escape and flee. When Schigolch returns with Lulu, the plan successfully carried out, the acrobat is disgusted by Lulu’s appearance and leaves, threatening to expose them to the police. Alwa, more fascinated than ever; decides to flee the country with her.

Lulu has been forced by extortioners to flee from her new dwelling. She now lives in the slums with Geschwitz and Schigolch; Alwa has been murdered by one of Lulu’s jealous customers. The three barely manage to keep alive on Lulu’s earnings as a street-walker. The last of Lulu’s customers is a sexual assassinator who murders her. Geschwitz, as a witness outside the door, is also killed by the escaping murderer.