The Summer Court is sending Gruffs (remember the billy goats? Yeah, those gruffs) after Harry, the Winter Court is sending Hobs, and Marcone has been kidnapped. All this results in a rather complicated (and dangerous!) affair that reveals a lot more about the Fallen and the Heaven/Hell conflict. 
 The last couple books seem to have been setting up the character pasts, with little more than vague hints about the overarching plot. Here, the characters are established and we appear to be moving into the big reveal. 
 I like Sanya quite a bit, and was glad to see him make an appearance. I also liked getting a bit more backstory about him - particularly with regards to being a black man growing up in Russia. 
 Fidelacchius finally became important again, as Harry tries to find a new owner for it. ((view spoiler)[I was concerned that Dresden was going to end up becoming a Knight, in addition to being a Warden and everything else. It would have just been so Mary Sue-ish. I kept hoping that Murphy would take it up instead, and was very glad when she was chosen. I was even more glad when she refused it, and gave a perfectly character-consistent reason. I'm still hoping that she'll become the new Knight eventually (particularly given how Fidelacchius seems to match Murphy's style of sword), but I'm glad that she didn't just take it up right away. That would have been very un-Murphy. (hide spoiler)]) 
 Overall, a solid addition to the series and I'm looking forward to reading the next!