"Also known as Alraune and Mandrake, The Unnatural is a kinky science fiction film, elevated by the bravura performance of Erich Von Stroheim. Playing a mad scientist, Von Stroheim artificially inseminates an addled prostitute with the sperm of a vicious murderer. The result of this unholy union grows up to be Hildegarde Neff, who is none too stable herself. Combining the worst traits of both her parents, Neff lures unsuspecting males to premature deaths. Just when Neff is about to consummate her first genuine romance with Karl Bohm, she is killed by Von Stroheim, who has long harbored incestuous feelings for his "foster daughter." Officially, The Unnatural was adapted by Fritz Rotter from a novel by H. H. Ewers...." - Hal Erickson, All Movie Guide
Erich Von Stroheim stars as the bizarre scientist in this off the wall science fiction film. This mad scientist artificially inseminates a prostitute with the sperm of a murderer, creating a beautiful but artificial and dangerous woman, (played by Hildegarde Neff). With neither a soul nor morals, consequently this "unnatural" woman induces disaster amongst all those around her. Taking a bit of the worst qualities of both "parents", she entices men into her control and then goes on to murder them. Jealous Von Stroheim ends up demolishing his own creation when he sees Neff taking a heavy liking toward a man, (played by Karl Bohm). Based on the book, "Alraune" by H.H. Ewers.