Though it is July, the widowed Bailiff teaches his younger children a Christmas carol. Charlotte, the eldest daughter, who is engaged to Albert, will be escorted to a ball that night by Werther, a young visiting poet: Werther arrives, rhapsodizes on the beauty of the evening and watches unseen as Charlotte prepares the children's supper, just as her mother had before she died. When the party has left for the ball, Albert returns unexpectedly after a six months trip. Disappointed at not finding Charlotte, he promises her sister Sophie he will return in the morning. Later that night, Werther and Charlotte come back from the ball. He has fallen in love with her, but his declaration is cut short when the Bailiff passes by, observing that Albert has returned. Charlotte tells Werther that she had promised her mother to marry Albert. Despite his despair, Werther urges Charlotte not to break her promise.
Three months later, Charlotte and Albert, are married. Albert tries to comfort the melancholy, gloomy Werther. Sophie also attempts to cheer him up, but when Charlotte joins them, he speaks of their first meeting. Disturbed, she tells him he must leave town until Christmas. Werther contemplates suicide, and when Sophie interrupts him, he rushes away. Charlotte consoles the tearful girl who does not understand his cruel behavior. Albert realizes that Werther must be in love with his wife.
Alone at home on Christmas Eve, Charlotte rereads the letters written to her by Werther. While she prays for strength, he suddenly appears. Charlotte tries to remain calm and asks him to read to her from his translation of Ossian. Werther chooses a passage where the poet foresees his own death, and when Charlotte begs him to stop, he realizes she returns his love. But she runs from his embrace with a final farewell, and Werther leaves, resolved to die. Albert enters, surprised to find Charlotte distraught. When a message arrives from Werther asking to borrow Albert's pistols, her reaction convinces him of her love for Werther. He makes her give the pistols to the servant herself, but when Albert has gone she hurries off, praying she may reach Werther in time.
Charlotte finds Werther mortally wounded. She declares her love, and he begs forgiveness. As he dies, the voices of the children outside are heard singing their Christmas carol.