This is the first book in the Dresden Files series by Jim Butcher.
I found this series through my typical... watch a TV show, find out it's based on a book, read the books... method. And just about invariably the books are better, but that's just the way that kind of thing works.
This falls under that contemporary fantasy genre which is just great fun. In this case the main character is a wizard (and advertises as a wizard, not that anyone believes him) who works as a PI in Chicago. And what is it about this particular genre that there's so many PI's/detectives?
So there's a missing husband, another wizard messing around with some seriously dark magic (who of course wants to kill Harry), giant scorpions, and a nasty new illegal drug.
Since this is the first in the series we also meet or are introduced to a bunch of people/things for the first time. Bob is quite a bit different than the Bob in the TV series, his personality is very similar, but his history is different. Murph of course, and the White Council enforcer dude whose name is escaping me just at the moment. There's fairies, and quite a bit about the "Rules" since the new wizard is very much not following said rules!