"Frau Holle is dead," reports an anonymous caller to the Eltville police. Shortly thereafter, child psychotherapist Sylvia Holler is found murdered, a girl from the Rheingau goes missing, and another is hospitalized with severe poisoning. Before Commissioner Mayfeld can decipher the motive behind these chaotic acts, the police receive another mysterious call. "The wolf is dead," announces the caller this time, leading Mayfeld onto the trail of a perpetrator obsessed with the Brothers Grimm.