Jim Butcher has crafted a fantastic read seemingly with ease. There are few books I get through as fast as I got through this one, just over one night it took me, would have been the one sitting if I hadn't started it so late in the evening.
So why is it so great? The fast pacing is definitely a boon to the reader there are no points where you're bogged down hearing about inane facts or trivialities that don't push the story towards is awesome climax. Don't take this to mean there is a lack of detail in the story though because there isn't it is a full formed story with great detail, it's a testament to the crafting that you don't realize how detailed it is until you look back at what you read. The characters are another boon to the experience Harry could be the long lost love child of Sherlock Holmes and Gandalf. He is the main character and a wizard in Chicago who specializes in finding things. That is a far to simple way to explain this very complex and multi layered character however, Harry is deeply flawed and knows it, he has an inherently good heart and wants to do the right thing however he is also dogged by his own dark past.
The rich detail of the world covers wizards, vampires, hard-nosed detectives, a bar purpose built for magical patrons, sociopathic gangsters, and unbelievably hilarious faeries (read it just for the faeries i tell you).