I liked this second installment. The mythology surrounding the crystals was interesting, and the tension between Kaitlyn and Gabriel is fun, even though she clearly loves Rob. I actually hate that Gabriel is the one to go evil, especially so soon after he'd found a place of equality with the others in the group. He's much more interesting than Rob, anyway, who is just a little too golden for me. I also would love to hear more about Anna and Lewis, who are fascinating characters in their own right. Despite the fact that Mr. Z wasn't in the book, but his threats were frightening enough- I'm ready to hear more about the pilot study and his plans for the kids. Book #3, here I come!