Near a polo field, in the bushes, Valerio finds the corpse of Giuliana Villani, dead of a drug overdose. The girl had two siblings, each very different from the other: Gianni, married to Wanda, in appearance a wealthy but humble man, the pride of his family; and the black sheep Walter, ex-mercenary from the Congo War who's now a painter with a disorderly life and a taste for J&B. While the police investigate, Walter makes his own search for answers.
The new science teacher Dr. Julian Olcott with a mysterious past arrives in an institutional boarding school for troublemaker girls. Along the night, the intern Mary Smith, who is blackmailing another teacher - Sir Alfred Whiteman - with some love letters, is slaughtered by a werewolf. The detective in charge of the investigation attributes the crime to a wolf, while her mate Priscilla believes she was killed by Sir Alfred. On the next days, other deaths happen in the school, reducing the list of suspects.