( The good, the bad and the unbelievable )
Our protagonist is Rio Conwy, a teenage girl with a secret: she is a siren. Yes, an honest-to-God Greek-myth siren who can control people (and objects, we later discover) with her voice. Rio and her twin sister, Bay, are sixteen and facing the choice given to every person in Atlantia: whether to stay Below or go Above. Rio has always dreamed of going Above and has intended to do so all her life, but six months before the story opens, the girls' mother, Oceana, the Minister of Atlantia, was killed. After this, Bay made Rio promise to stay Below. So Rio, denying what she has always wanted for the sake of her sister, does so...and Bay pulls an about-faced betrayal by announcing her irrevocable choice to go Above.
The rest of the story revolves around Rio's quest to discover why Bay did that, and how it ties in to the death of their mother and eventually the future of Atlantia and their entire society.
The relationship between Rio and Bay, and their aunt Maire (also a siren) and mother Oceana is the best thing about the book. The theme of the book is the love between sisters, and Ally Condie explores this in deceptively simple, lovely prose. All four women are real, believable characters, and the book comes full circle to end with Rio and Bay, as it should. (There is a romance, but it's appropriately kept on the back burner.) I'd give this aspect of the book four stars.
Unfortunately, there's the rest of it, in particular the worldbuilding. Which is to say, very little, and what there is doesn't make much sense. We don't even know if this planet is Earth (although their gods are familiar-sounding animals, and blue-winged bats live in Atlantia), or if this takes place in the future or past. One could make a case for this taking place several hundred years in the future, when the full catastrophic scenario of climate change has come to pass: the sea level has risen, the land masses are devastated, and humanity has retreated either to the deep ocean or to the moon and/or Mars (Rio's boyfriend True makes a reference to another civilization that Divided about the same time theirs did, only part of this civilization went into the sky). But you'd think, with the technological sophistication shown by humanity's ability to build freaking undersea cities, they would also have records of this. They don't seem to, and nobody seems to care, which was very frustrating for me as a reader.
The bigger problem, for me, is the entire concept of the sirens. This gives the story a very mythic quality, which was obviously the author's intention. However, this entire thing is an ill-fitting square peg in a round hole, because there is almost no explanation as to how the hell sirens can even work. Sure, I'll grant that after a few generations of underwater living, genetic mutations will begin cropping up. I'll even stretch my suspension of disbelief really far and give the idea of someone's voice somehow influencing brain chemistry and/or waves and making people do as you say a pass. But when a siren starts "storing" voices in walls and seashells like invisible disembodied tape recorders, or a siren's voice can cause coins to float when they should by all the laws of physics sink, or that same voice can cause little mechanical fish to move in ways they otherwise wouldn't...sorry. Nope nope nope.
And since the main character is a siren, you see the insurmountable problem.
It's frustrating, because as I read on through, I kept feeling that this book should have been torn apart and rebuilt from the ground up. Only the characters and the relationships, and the beautiful prose, kept me going to the end. This book is supposedly a stand-alone, fortunately. If it had a sequel, I would avoid it like the plague.