I wanted to like this book so badly. I adored the first book; I felt it brought up a lot of moral questions that are hard to answer and performed a beautiful dance around many hard decisions. 
 The second book disappointed me somewhat. It had lost that special something that the first book had used to keep me wrapped up in it. 
 I'm sorry to say this final book didn't do much better. 
 The big problem was that I really could not connect with Ari. I tried very hard, but I felt like a spectator to her problems rather than like I was living through them and experiencing them with her. 
 Don't get me wrong, this book was very action-packed and would often jump from one encounter to the next. The relationships became more complex. There were joys, there were tears. Ari made new friends and lost old ones. 
 It had all the ingredients to be a really good finale, but for whatever reason Collide failed to transport me to Ari's world the way that Gravity did.