i can understand why there are people that don't like this ending, but even if I'm left wondering what will happen to Amy and Elder in their new home, I'm satisfied with the book, the intrigue and the ending (although it felt rushed). 
 if razorbill hadn't changed the cover for this last book, this series would have had a prominent place in my bookshelf. I never warmed to Amy or Elder, but they were very good characters and i really enjoyed their love story. the explanations that were given at the end didn't entirely convince me, but they made sense for my not-scientific eyes and that's enough. 
 in the end, it is a good YA series and I've great expectations for whatever Beth Revis brings us next.