Based on Hermann Sudermann's novel, two life-long friends get involved with the same beautiful woman.
In the army Ulrich von Eltz (Lars Hanson) sees that Leo von Harden (John Gilbert) is missing and reports that he is ill. They get extra work. On leave Leo greets his mother (Eugenie Besserer) and Ulrich's sister Hertha von Eltz (Barbara Kent). Leo sees Felicitas (Greta Garbo).
Leo and Ulrich recall their friendship as boys with Hertha when they became blood brothers on the Isle of Friendship. At a ball Leo and Ulrich greet Parson Voss (George Fawcett). Hertha wants to dance with Leo, but she is not yet sixteen. Leo dances with Felicitas, and in the dark they kiss.
Leo lays his head on Felicitas in her bedroom. He says he gets out of the army in five months, and then they can be together. She gives him her ring to remember her. Count von Rhaden (Marc McDermott) comes in, and Felicitas says that he is her husband. He challenges Leo to a duel and says they will say it is over cheating at cards. They use pistols, and Felicitas puts on black.
Leo meets Felicitas in a park and says he had to enlist for five years in Africa. She says she will wait, and the parson sees them. Leo says goodbye to his mother and asks Ulrich to visit Felicitas. Hertha says goodbye too. Ulrich calls on Felicitas and offers his help, saying he is rich.
Three years later Leo gets a letter from Ulrich saying that he can come home. On the way Leo thinks of Felicitas. Ulrich welcomes him at the train and says that Felicitas is his wife. Leo finds his mother with Hertha, who has lived there since Ulrich's marriage. Ulrich asks Leo to forget the duel. The parson tells Leo that he must give up Ulrich's friendship because he is still in love with Felicitas. He says the devil uses a beautiful woman to reach us through the flesh.
Leo gets a note from Felicitas to meet her on the Isle of Friendship. She explains that she was alone and that Ulrich was so kind. She asks Leo to come back to Ulrich. Leo goes to Ulrich, who is happy and tells Felicitas. The parson sees Felicitas come into his church with Leo and Ulrich, and he preaches about David taking Uriah's wife.
Leo objects to Hertha messing with his papers. Felicitas comes to see Leo while Ulrich is in Munich. She cries, and they go out into the snow to talk. She finds a fireplace. Leo wants to be honest with Ulrich. Felicitas kisses Leo, who says he must die or go away. She suggests they both go away.
Felicitas is ready, but Ulrich comes home and gives her a diamond bracelet. She lets Leo come in quietly. She says they need not run away. Leo chokes her, and Ulrich comes in. Felicitas says that Leo is mad and wanted her to go away with him. Leo admits it, and Ulrich suggests a duel on the Isle.
In the morning Hertha asks Felicitas to stop the duel, and then she prays. Felicitas gets upset and then embraces Hertha. Felicitas rushes across the ice, which breaks, causing her to drown. Leo and Ulrich both refuse to shoot. Ulrich says that he understands, and they embrace.
This tragic romantic drama reflects the social dangers
that occur when human passion gets fixated on a person who is
married to someone else. In this case the bond of friendship proves
to be stronger than the illicit romance.