The Dream Thieves (The Raven Cycle, Book 2)

Now that the ley lines around Cabeswater have been woken, nothing for Ronan, Gansey, Blue, and Adam will be the same. Ronan, for one, is falling more and more deeply into his dreams, and his dreams are intruding more and more into waking life. Meanwhile, some very sinister people are looking for some of the same pieces of the Cabeswater puzzle that Gansey is after....