The Dream Thieves didn't meet the high standard set by The Raven Boys. Many books suffer by what I call the "sequel syndrome," where the sequel can't hold a candle to the original, and unfortunately, I think The Dream Thieves fits this description.
It seems as though Stiefvater wrote The Raven Boys without realizing how much character development or details were needed to create this world. Maybe she wrote The Raven Boys without knowing just how big the series would be and so she left much of the characterization up to reader's imagination. Whatever the season, a sequel shouldn't carry THIS much detail and weight in comparison to the first book; it should be more evenly spread out over the series. The sheer volume of detail was exhausting and diminished my overall enjoyment of the book. I felt like we were finding out traits and quirks about the main characters that should have appeared in the first book.
The Dream Thieves does have an intriguing premise, so it IS worth the wait to get to the exciting bits at the end. The book's plot is darker and more complex, and the exciting end battle submerges the reader in the realm of the fantastic. It ends with a to-the-death match that will have you anxiously turning the pages to see what happens next.
Readers beware that this is a TEEN book (not YA). There's [many] F-bombs, drugs, violence, and other subject matter that is considered inappropriate for younger audiences. The supernatural takes on a larger role in this book, with Ronan able to dream things into existence and with the ley lines feeding powerful and dark events. It's not just the continuation of the Cabeswater/Glendower plot; there are several story arcs interwoven throughout the book, including romances, betrayal, and murder.
Despite my qualms with its length and the distribution of content, The Dream Thieves is a great book for teens and the series is definitely a must-read. Maggie Stiefvater is one of the top teen writers today. The book ends on another cliffhanger, guaranteeing that I will return for the next book. Ultimately, this is an exciting story that makes for a thrilling read.