Oops! I read this in November and forgot to post on it.
Allegiant is the third book in the Divergent Trilogy, a dystopian YA series. It concludes the tale of Tris Prior, a teenage girl who has chosen to live in a faction of society different than that of her family. Just as she has chosen her faction to train in and be a part of, the society that she grew up in has started to crumble. Tris is considered a dangerous person as she is 'divergent' meaning that she does not have a clear aptitude for just one faction, but three. The other main character in the series is Tobias who is one of Tris' trainers. He and Tris have developed a romantic relationship.
This book is different from the others as it changes point of view between Tris and Tobias each chapter. I did find this confusing at first as I was used to reading everything from Tris' point of view. Having now completed the book I understand the author's purpose in writing this book that way. There were many elements of the society around them that needed to be explained and the best way to do that was to use the two different characters.
I did enjoy this series and would recommend it to others. I look forward to the movies coming out (the preview for the first I saw at the theatres before Catching Fire). It is well worth your time.