This is the fifth version (the best version being the 1928 silent with Paul Wegener and Brigitte Helm) that writer Fritz Rotter bases on the Hanns Heinz Ewers novel. Erich Von Stroheim plays defrocked mad scientist Professor Jacob Ten Brinken, who has created a baby by means of artificial insemination--which was the reason for his removal from the university. The Professor used the sperm from a convicted murderer and the egg from a slum-living Hamburg waitress of easy virtue. He names the baby Alraune (the German name for the narcotic mandrake root), and raises her as his daughter without telling her the secret. Brinken keeps her a secret from all but his servants, as he fears she has inherited her parents' evil. But his sponging university student nephew, Frank Braun (Karl Boehm), shows up one night at his mansion to hit the Professor up for some money to pay his tuition for medical school and discovers the beautiful Alraune (Hildegard Knef), and immediately falls in love with her. Alraune has just run away from a convent where she felt like a prisoner, and is also immediately attracted to the young man. They make plans to be together in Paris where Frank is heading the next day to study medicine; that is, after being turned down by his uncle he receives tuition money from the wealthy Princess Wolkonski--interested in having Frank marry her airhead daughter Olga. But in a fit of anger, before Frank leaves with Alraune, Brinken tells his nephew about the artificial birth and he leaves without her.