I enjoy Jim butcher as a writer. He writes some marvelous dark fiction, with normally colorful characters. I am not, however, a fangirl, so this is going to be a brutally honest review. 
 Keep in mind this review is on the 100 pages. 
 Writing is not one of his problems. We are thrown around from pov to pov with nothing to keep an adults attention. you got it. a 640 page ya book. although, I've seen kids movies with more attitude than this wretched waste. 
 expectations are high. From one look at that cover... we all see adam baldwin on that cover. Grimm was expected to be some badass, cowboy, pirate instead of some dueling twerp. The side characters that dominate the scene feel mostly like fill in. Unless, god forbid they all join up like a hapless band of scoobies. Nooooooooo! 
 World building is very vague. It's left to reader deduction too often. I am not writing this story damn it. 
 Even the first battle was avoidable. It annoyed me to no end that they engaged in the first place. Running would have been the best option, but we just had to throw in an airship battle. For the hell of it.