It took me a while to get into the book. I think the weight of the series is an issue. There's so much that has happened, so many subplots, that you have to wade through a bit before getting on with it. It frustrated me a bit, but it's still a Butcher book, so I endeavored. 
 Dresden finds out he's a father and that his daughter's been kidnapped by the Red Court vampires. They've also done a good job of cutting off sources of help. Dresden is forced to make a deal with Mab. A lot of messing around ending in a gigantic battle.