Harry sets out to solve a bunch of murders in the city, apparently caused by werewolves. He manages to run into every type of werewolf there is and either befriends or executes them.
Tropes present in Fool Moon include:
- Chekhov's Gun: Bob lists all the different types of werewolves at the beginning of the book. The hexenwulf belts are explained in Cold Days to have been given by an agent of Nemesis.
- Lesser of Two Evils: John Marcone, as per usual.
- Monster of the Week: a Loup-Garou (super-werewolf); a bunch of lycanthropes (humans with the minds of wolves)
- Savage W Olves: Wolves are villans here.
- Sidekicks: Murphy (sort of), The Alphas (a werewolf gang)
- We Used to Be Friends: Murphy, who no longer trusts Harry, gets so angry at his suspicious behavior that she arrests him and punches him out, breaking a tooth
