Dang... I hadn't realised there would be a fifth book. That ending is slowly killing me already, but I guess I'll just have to be patient! 
 As for the rest of the book, it was good. Well-written as always and I liked seeing a Selection with all boys instead of girls. I really missed America and the other characters from the first three books, though. Every main character from then is a minor character now, only showing up occasionally, and I would have loved to view parts of this book through America's eyes or Maxon's. 
 Eadlyn was much harder for me to relate to than America was. She's arrogant, bossy, and rather cold; and although I sometimes like such characteristics in a heroine, Eadlyn just didn't really do it for me. The way she treats her maid throughout the book had me shaking my head often. Actually, the way she treats everyone throughout the book made me cringe. Her interactions with her brothers were nice, but during the majority of the story, she is rather rude to the Selected and even though she is eighteen and has been training to become queen for years, she's often acting like a spoiled teenager towards her parents. And she IS a spoiled teenager, of course; but given the way she talks about herself and everyone else, how she obviously thinks of herself as so much better and more important than other people, I'd think she would act differently. 
 She changes a little throughout the story. Her character has not fully developed yet, I think, and I have hope that she will become more likable in the next book. For now, however, I found her rather obnoxious. She constantly reminds everyone that she will be the queen, she constantly complains about everything and balks at every sacrifice asked of her (of course, sometimes that is justified, but definitely not always), and she always orders everyone around and is overall rather rude towards other people. Actually, this quote from Kile on page 25 describes perfectly how I felt about Eadlyn most of the time: 
 "You're not queen yet, Eadlyn. Take it down a notch." 
 In conclusion, I enjoyed reading THE HEIR, but I enjoyed reading the original trilogy more. I've got the fifth book here now, though, so I'm going to start reading that one and see where Eadlyn's story goes!