Good, but a missed opportunity. 3.5/5 stars. 
 This review was originally posted on my book blog. 
 My hopes were high for The Raven King. I was hoping for something epic. After sticking with the characters through three previous books I was expecting a grand finale, a mind-blowing conclusion which was both stunning and satisfying. 
 So I'm a bit disappointed that I can summarize my reaction to this book as "meh" and "eh?" 
 Don't get me wrong, it was fine and enjoyable enough, but it could have been so much better. Firstly, I'm convinced this series would have been better as 3 or even 2 books. There's a lot of treading water. And while Stiefvater treads water in splendid and often beautiful prose, after a while even the high quality of the writing wasn't enough to stop me longing for her to shift the story along. 
 Also, while several significant events meant some important plot threads were wound up nicely, I felt too many things were left hanging. Too many questions unanswered. And several times, even though I read the previous three books recently and remember what happened, I was completely bamboozled as to what the heck was going on. 
 Coming back to those significant events... I thought they were rushed. Almost skimmed over. Things we've been waiting for and the author has been building up to for 4 books and then they're all done in a couple of paragraphs?! I felt short-changed. 
 Overall: The Raven King is ok and that's not good enough when the characters and set-up (developed with great skill and care in the previous 3 books) were so promising. I fear those hoping for fireworks, surprises and resolution will be underwhelmed :-(