The action takes place in Germany in the eighteenth century, at the court of one of the German Dukes.
The son of President von Walther is in love with the daughter of a simple musician, Louise Miller. Her father treats this with disbelief, since the marriage of an aristocrat with a petty bourgeois is impossible. On the arm of Louise, the presidential secretary Wurm aspires, he has long visited Miller’s house, but the girl does not feel any feelings for him. The musician himself understands that Wurm is a more suitable party for Louise, although he is not happy with Miller, but the last word here is for the daughter herself, the father is not going to force her to marry anybody, Wurm informs the president about the infatuation of his son by the daughter of the philistine Miller.
Ferdinand returns home. Father tries to talk to him about his future. Now he is twenty years old, and he is already in the rank of major. If he continues to obey his father, he will have a place in the neighborhood of the throne. Now the son must marry Lady Milford, which will finally strengthen his position at the court. Major von Walter refuses the offer of his father to marry a “privileged charmer,” he dislikes the president’s deeds and the way he “dresses” them at the court of the duke. The place near the throne does not appeal to him. Then the president suggests Ferdinand to marry Countess Ostgeym, who is from their circle, but at the same time did not discredit herself with a bad reputation. The young man again does not agree, it turns out, he does not like the countess. Trying to break the stubbornness of his son, von
Ferdinand breaks into the house of Lady Milford. He accuses her that she wants to marry him with her marriage. Then Emilia, who is secretly in love with the major, tells him the story of his life. Hereditary Duchess Norfolk, she was forced to flee England, leaving her entire fortune there. She had no relatives. The Duke took advantage of her youth and inexperience and turned her into an expensive toy. Ferdinand regrets his rudeness, but tells her that he can not marry her, because he loves the daughter of the musician Louise Miller. Emilia’s plans for personal happiness collapse. “You are ruining yourself, me and another third person,” she says to the major. Lady Milford can not refuse marriage with Ferdinand, as she “does not wash away shame” if the subject of the duke rejects her, so the brunt of the struggle rests on the shoulders of the major.
President von Walter is at the musician’s house. He tries to humiliate Louise, calling her a corrupt girl, who dexterously enticed the nobleman’s son into her networks. However, having coped with the first excitement, the musician and his daughter are held with dignity, they are not ashamed of their origin. Miller in response to the intimidation of von Walther even points him at the door. Then the president wants to arrest Louise and her mother and shackle them to the pillory, and throw the musician himself in jail. Arriving in time Ferdinand sword protects his beloved, he hurts policemen, but this does not help. He has no choice but to resort to the “devil’s means”, he whispers in his father’s ear that he will tell the whole capital how he removed his predecessor. The President in horror leaves Miller’s house.
The way out of the situation is prompted by the insidious secretary Wurm. He offers to play on the feeling of jealousy Ferdinand, throwing him a note written by Louise to a fictitious lover. This should persuade his son to marry Lady Milford. A false lover of Louise, the president persuaded to become Marshal von Kalb, who along with him made fake letters and reports to remove his predecessor from his post.
Wurm goes to Louise. He informs her that her father is in prison and he faces a criminal process, and his mother is in a workhouse. The obedient daughter can release them if she writes a letter to the dictation of Wurma, and also takes the oath to recognize this letter as voluntary. Louise agrees. The letter, “lost” by von Kalbom, falls into the hands of Ferdinand, he calls the marshal to a duel. The cowardly background of Kalb tries to explain everything to the major, but passion prevents him from hearing frank confession.
Meanwhile, Lady Milford arranges a meeting with Louise in her house. She wanted to humiliate the girl, offering her the place of the maid. But the musician’s daughter shows such nobility in relation to the rival that humiliated Emilia leaves the city. She flees to England, handing out her property to her servants.
Survived so much in recent days, Louise wants to end her life, but her old father returns home. With tears he manages to dissuade his daughter from a terrible act, Ferdinand appears. He shows Louise a letter. Miller’s daughter does not deny that it is written with her hand. The major is beside himself, he asks Louise to bring him a lemonade, the musician sends President von Walther to the President asking him to send a letter from him and say that he will not come for dinner. Left alone with his lover, Ferdinand imperceptibly adds to the lemonade poison, drinks himself and gives a terrible potion to Louise. The imminent death removes the seal of the oath from Louise’s lips, and she confesses that she wrote a note on the orders of the president to save her father from prison. Ferdinand in horror, Louise dies.
Von Walter and old Miller come into the room. Ferdinand accuses his father of the death of an innocent girl, he points to Wurm. The police appear, Wurma is arrested, but he does not intend to take all the blame. Ferdinand dies, before he dies, he forgives his father.