Saint Peter's Wolf, by Michael Cadnum
You would think it's child's play to write a good werewolf story. Use a full moon, throw in an okay guy who probably doesn't have too much going on in his life, get him into a nasty accident at the wrong end of a Gypsy curse, mix in a love interest...that's all there is to most basic werewolf stories, right? I mean honestly, that's pretty much your general heroic cycle, if you're simplifying it for a toddler.
Yet, I rarely run into a werewolf story that leaves me thinking 'I really enjoyed that. It hit all the bases, and ended up being a well-rounded story about man's struggle with his inner beast.' Honestly, most of the good ones tend to be over 50 years old, too. If you're familiar with the film 'Wolf' with Jack Nicholson, which time and again I make myself watch once a year hoping I'll somehow manage to actually think it's a good movie, because it does have a great cast and cool effects...
Saint Peter's Wolf...is everything that story should have been. It is very similar, but it's done right. It also has a very unique twist on exactly how the 'curse' is obtained, and keeps the werewolf as your general quadrupedal beast, rather than a man with huge teeth, a bad temper, and a body hair issue. It's also got a fascinating protagonist who discovers that becoming the monster is actually a little bit better than what he's already got going on. At any rate, it's not strictly horrifying...but it's a very good read.