First, I have to say thanks to my employer, Barnes and Noble, and also Harper Collins Children's Books for giving me the chance to read this as an Advanced Readers Copy.Okay, once again, I think that I give this a 4 instead of a 5 because I didn't like the ending! Not that it wasn't a good ending, don't get me wrong. In fact I wish I could rate 4.5 instead of just 4 or 5, but the ending irritated me. I'm really a bit tired of love triangles. I won't say who the love triangle is with, I'll let you read the book itself and see who the 2 boys are, but I don't feel it was needed with this series. To me, the 3rd book could have been about the search for Lena's mother, who she glimpses and comes in contact with briefly in this book. And trying to help the guy she now has feelings for survive the "deliria" she now knows well. I was so happy when I found out that there was a second book in this series as I was so mad with the way the first one, Delirium, ended. It sucked that she lost her love, Alex at the end. In a way it made me as mad as the first and only Nicholas Sparks book I ever read, in that it made me feel all good inside and like the system could be overcome and people could be happy, but then BAM! true love is gone because one of them dies. Pandemonimum is a really good second book. As many sophomore books have been lately, they've just kind of moved the series along, didn't necessarily quite live up to the original, but were necessary to keep the series going. This one blows that all away. It moves the story along with enough action and plot to keep up with the original in my opinion.Lena is now living in the Wilds. We are told her story through flashbacks in between what is happening when she must re-enter the Society to help with furthering the fight for those who want their own choice to love or not. When she first gets to the Wilds she is in bad shape, she has been on the run, by herself, and without Alex, she doesn't know how to survive, and so barely manages to stay alive, until she is found by members of the resistance, or Invalids, as they are called in the cities. They nurse her back to health, and soon require her to start contributing to their camp in a way that everyone else does. And as soon as she does start feeling better, Lena goes back to what we know she loved best in Delirium, running. Every winter they must move their camp south in order to survive. And they must send scouts out to make sure their way is safe. Well, as they move along, sooner than planned due to a message from their contacts on the inside that things have gone wrong, they end up losing a few of their group. This sends them in to the city to try to help further the resistance. Lena must go in undercover, and join into the opposition as a member. At a big rally, things go wrong. Lena is following Julian, the leader of the DFA - Deliria Free America's son. And she gets kidnapped at the same time he does. They must fight their way out to freedom, and find that there may have been some betrayal by someone they wouldn't have suspected.Often books that jump back and forth like this can be confusing, but the way the author does this really worked for me. I really liked this book, except for the ending, mind you.One other thing I have to point out that amused me so much I had to tweet about it as I read it. The vans that are used kind of as police type vehicles, they have the name of the department, the City of New York, Department of Correction, Reform, and Purification as an acronym which reads: CRAP. Funny? Or is it just me?