Fun start to the Kate Daniels series. It's not high art (sometimes it starts feeling like it really wants to be a bodice-ripper), but it's a good urban fantasy premise (sometime in the Very Near Future, magic started hitting the world in waves, encouraging the supernatural to come to the surface and periodically disrupting technology) with an appealing kick-ass heroine.

In this first volume, someone is (quite violently) killing members of several of the supernatural-related communities, to set them against each other. Kate needs to figure out who and why, and deal with them. (Whilst also dealing with several men who have more or less savory interests in her.)

Sets up a ton of backstory hooks, which I assume will pay off over the subsequent books.