The Dream Thieves is a fantastic follow-up to The Raven Boys. While the first book set up the boys' relationships, Blue's entrance into their group, and the search for Glendower, the second book doesn't need to bother with filling the reader in and instead launches you into the intrigue. I say intrigue because while it's not constantly action filled, there's always something happening. 
 The first book just scratched the surface of all that is possible within Henrietta, and in The Dream Thieves new information on the magic within the town was revealed with increasing rapidity. 
 One of my favorite things about "The Raven Cycle" is the fact that the story isn't just about finding Glendower. It's also about the shifting relationships of Gansey, Adam, Noah, Ronan, and Blue. They're not just a group of happy-go-lucky friends off to find a dead king. They experience conflicts and shifts within the group, Adam with his insecurities and pride clashes against Gansey, Ronan is just generally a little out of control, Blue feels like she'll never really be one of the group, and Noah is, well, dead. They change and grow, discovering new things about themselves and each other. They're never stagnant. And then there's the whole thing with Blue's feelings towards the boys. As I said in my review of The Raven Boys, I appreciate the fact that she doesn't experience insta-love with any of the characters. Her feelings grow and change as well, but there isn't any undying-love pledges happening. And even better, when Stiefvater writes the "romance" scenes of the book (what little there are) she doesn't make them seem more important than the other relationship scense of the book. All of the relationships are treated equally, friendship, romantic, antagonistic and that is, honestly, quite a relief, and makes me love series even more.