Karl Muller and his foster brother, Stephan Brenner, leave their farm in the Austrian countryside, and travel to Vienna to study medicine. Karl is in love with his foster sister, Lottie Brenner, and would rather work as a farmer, but in deference to the wishes of his foster mother, Mrs. Brenner, he studies hard and is named valedictorian of his class. Stephan, on the other hand, enjoys drinking and flirting more than studying. One night, while drunk, he performs an illegal operation on his girl friend Anna. After she becomes very ill, he confesses everything to Karl, who agrees to try to help her, even though he does not yet have his license. While Karl is with Anna, she dies, and he takes full blame for the operation in order to spare Mrs. Brenner's feelings. He is not allowed to graduate and spends time in prison. After he leaves prison, he returns home to find that Stephan has died. Karl is eager to return to farming, but after he successfully operates on a boy injured in an accident in front of the house, Mrs. Brenner convinces him to pose as Stephan and continue his work as a surgeon. Karl travels to Vienna to work with earthquake victims and is extremely successful. However, now that he is supposed to be Lottie's brother, they are forbidden to marry. Mrs. Brenner forces Lottie to announce her engagement to another man but, seeing how unhappy she is, remorsefully writes the truth about Karl to his supervisor. Although the board of directors dismisses him, Karl begs to be allowed to operate on his foster mother, who has collapsed in the street. They relent and the operation is a success. No longer a doctor, Karl finally marries Lottie and they return to the land.