The second in the Harry Dresden, wizard-as-PI in modern-day Chicago series. In this one he deals with werewolves of various varieties: if it has some background in legend, it shows up here. More satisfying, I think, than the first, because Harry actually learns something besides the details of lycanthropy. I was bugged by the way the first book had Harry withholding vital information from his friends "to protect" them (actually just so the plot would move forward); in Fool Moon he sees the error of his ways, although he doesn't actually act on that realization. Maybe next book.