A scientist creates a beautiful "perfect woman", but since she is artificial, she seems soul-less and with no sense of morality, she brings ruin to all around her.
Medical student Frank Braun [Carlheinz Böhm] arrives at the estate of his uncle,Professor Jacob ten Brinken [Erich von Stroheim], to ask for money so that he can continue hisstudies. His uncle is not home, but Frank is surprised to see a beautifulyoung girl seated on the railing of a second story porch at the top of atrellis. When Frank asks about the girl, the servant denies that they haveany guests and tells Frank to come back tomorrow to talk with his uncle.But Frank doesn't want to wait until tomorrow. He tells his friends RalphGoutram [Rolf Henniger]and Gerald [Harry Meyenrin] about the girl; the three of them decide to investigate. Theyreturn to search the estate. Ralph and Gerald both catch glimpses of thegirl, but it is Frank who finally catches up with her. She invites him tomeet her the next day at 3 PM near the sundial.
In fact, it was about this girl that ten Brinken had gone away. Sheis his daughter Alraune [Hildegard Knef], and she ran away from the convent school. Notthat the Mother Superior is unhappy about Alraune leaving. Alraune has areputation at the convent of causing trouble. She reads "obsceneliterature," and she incites the other girls to do nasty things, eventhough Alraune herself always comes out blameless. Good riddance, she says.
When Frank finally gets to see his uncle, ten Brinken refuses to givehim the money for his studies, so Frank goes to see an old family friend,Princess Wolkonski [Trude Hesterberg]. The Princess has eyes on Frank as a husband for herdaughter Olga [Julia Koschka], so the Princess offers to loan Frank the money he needs tocontinue his medical studies on the provision that he study at theSorbonne in Paris (she wants to keep him away from Alraune). She alsoexplains to Frank that his uncle was once a medical doctor, but he wasexpelled from the university for conducting unusual experiments. Shethinks it's for this reason that ten Brinken doesn't like young Frank, whois studying to become a doctor.
The next day, Frank meets Alraune at the sundial. They profess theirlove for each other. When Frank informs Alraune that he'll be leavingtomorrow for Paris, Alraune is extremely pleased and tells Frank that shewill accompany him. They arrange to meet the next day at the sundial. Whenten Brinken learns about Frank's meeting with Alraune, he changes his mindabout the loan. But Frank refuses the money and tells ten Brinken of hislove for Alraune, so ten Brinken tells Frank the truth about her. He givesFrank a diary in which he describes the circumstances surrounding herbirth. Aided by Princess Wolkonski, ten Brinken artificially impregnated aseedy prostitute with the sperm from a murderer about to be hanged.Alraune, he says, already shows evidence of the evil characteristics ofher true parents.
Horrified by the truth of Alraune's ancestry, Frank leaves for Paristhat night and fails to meet Alraune as planned. Letters that Alraunesends to Frank come back "refused". Feeling betrayed by Frank, Alraunebegins to live up to her legacy. First, she suggests that her father buy aseemingly worthless tract of land, but when they ride out to survey theland, they uncover a sulfur spring, spouting water that can be developedinto a successful health spa. Olga comes to stay with the ten Brinkenswhile her mother travels to Paris. When Olga receives a letter from hermother regarding Olga's engagement to Frank, Alraune convinces Olga thatno man who really loved her would send his love through his fiancee'smother, so Olga attempts suicide by poison.
Alraune takes to flirting with men who are infatuated with her. Shegoes horseback riding in a rainstorm with Gerald. She goes riding in acarriage with the coachman Mathieu [Hans Cossy]. She poses for Ralph so that he canpaint her. When one of Alraune's necklaces comes up missing and is foundin the luggage of her governess, Mlle Duvaliere [Denise Vernac], Alraune requests thatMlle be dismissed. Later she learns that it was Dr Mohn [Harry Halm] who took the keyto Alraune's jewelry box, stole the necklace, and planted it in Mlle'sluggage, all to gain Alraune's favor. Frank returns from Paris with hisdoctorate, but still he refuses to have anything to do with Alraune.Distraught by Frank's continued coldness towards her, Alraune tires of herconquests, and they begin to die. Mathieu's carriage runs over a cliff.Ralph catches pneumonia and dies. Gerald dies in a duel with Dr Mohn.
No man seems to make Alraune happy. Alraune herself wonders whethershe is capable of loving and seems motivated by only one thing -- FrankBraun. She begs Frank to help her. When Frank sees Alraune cry, herealizes that everything he was told about her was untrue...she does havefeelings for others, she has a heart, she has a soul. Frank takes Alraunein his arms, and they plan to go away together. Alraune tells her fatherabout her love for Frank, but ten Brinken refuses to let her go. Instead,he gives her the diary and tells her to read about her parents. He warnsher that, if she goes away with Frank, she will destroy him, too, just assurely as she destroyed the others. Alraune decides not to go away withFrank.
Days pass. Dr Mohn threatens to go public with ten Brinken's illegalexperiments. Ten Brinken plans to take his money and move away fromGermany with Alraune. Princess Wolkonski worries that revealing tenBrinken's secrets will ruin her, too. Frank can think of nothing otherthan Alraune. Together, Frank and the Princess go to see the ten Brinkens.While the Princess argues with ten Brinken, Frank pursues Alraune throughthe snow. Alraune keeps seeing images of her dead suitors, and she faints.When she comes to, Frank tells her that he loves her and tries to convinceher that she had nothing to do with the deaths, but Alraune sees herselfas the bringer of destruction because she is nothing more than a horribleexperiment, brought into being by the evil thoughts of a depraved man.Frank assures her that both good and evil are passed into each individualand that the good in Alraune can win over the evil. The evil thing is thatshe was brought up without love. Whoever is brought up without love issick, Frank moralizes.
As Frank carries Alraune back towards the house, her father pulls outa gun and shoots her. Alraune dies, and ten Brinken is hanged. [Originalsynopsis by bj_kuehl]
