This will be short and sweet, because I am against even the hint of spoilers. I got my hands on The Raven King earlier than anticipated because it was not marked a strict on sale by the publisher. This means that booksellers can put it out for sale when they receive their shipment. Which means some readers can get their hands on it before its official release. 
 Stiefvater never really takes the plot path I expect, which is probably why she's considered a master at her craft. This series is a little more windy than most supernatural series. We have a clear goal of finding Glendower, but often through the series we aren't really actively pursuing it as much as we can. Part of this, in my theory, is because the character's themselves are afraid to see what comes after the end of this journey. Part of it is that it is more in fact about the character's journey. 
 The thing that struck me again about Stiefvater's writing this go round is how specific it is. Even with the humor and the quips, it is obvious, in the most natural of ways, that every word has been considered for precision. This is a tight novel. It is clear that Stiefvater had a path, even if I occasionally got lost along the path. For instance, the side characters could be distracting, because we didn't really get to follow their journey. And yet, Stiefvater somehow managed to make a short, clear journey for many of them anyway. 
 Still, it's or core group that shines here. If Stiefvater excels at making minor characters count, her main characters are heartbreaking simply in that I cared about them so much. 
 The ending could feel a little rushed, but really it was probably just the necessary harried pace with the increased stakes. And, after 4 books, any ending at all feels sudden.