The humanoid-shaped mandrake root or Mandragora officinarum was widely believed to be produced by the semen of hanged men under the gallows.

Alchemists claimed that hanged men ejaculated after their necks were broken and that the earth absorbed their final "strengths".

[citation needed] The novel deviates from the myth by concentrating on the issues of artificial insemination and individuality: genetics versus environment.

A scientist, Professor Jakob ten Brinken, interested in the laws of heredity, impregnates a prostitute in a laboratory with the semen of a hanged murderer.

The girl, Alraune, suffers from obsessive sexuality and perverse relationships throughout her life.