** spoiler alert ** 
 I'm having trouble organizing my thoughts about this book. Let me just do some lists: 
 Things I liked: SO MUCH info about the people outside, the return of Sam-and-Astrid, Edilio is gay! (which seems so obvious now, and with Roger! it makes so much sense but never occurred to me), Caine kinda sorta redeems himself (maybe? or at least joins the correct side), Pete is even more dangerous in death (also, not quite dead), Brianna remains a huge badass and kind of understands herself more, Sam grows up a bit, we find out how Sam and Caine got separated, Dekka befriends Orc (who knew?), the light returns. 
 Things that gave me sad face: the horrible darkness, Dekka's horrible depression, the horrible murders of small children (and poor Howard, who I liked to some extent), WHAT IS WRONG WITH PENNY, Diana's horrible birth and creepy baby, and most of all, the ending! I mean, basically, it seems that these kids are lost whether they get out of the FAYZ or not. How horribly depressing. And more than that, the idea that nobody outside could ever understand the nature of life in the dome. Because it's so seriously weird, so how could they understand? Oh, and then the small matter of Gaia, who is basically a literal demon child. And obviously she will be unkillable. I don't know how that can possibly end well. 
 Although I guess "ending well" is kind of out of the question for the FAYZ now. 
 Another thing that bears mentioning is the complexity of the writing. This is the most deeply layered GONE book yet, and I appreciated the level of detail and foreshadowing. 
 Finally, can someone pleeeeeeease kill Drake in Light? PLEASE, I'M BEGGING YOU MICHAEL GRANT.