I was so glad this book wasn't about mermaids. I was really afraid it would be with a title like Atlantia. But there was little to correlate this tale to the common ones of Atlantis. And for that I was really grateful.
Rio and her twin sister are part of a society that lives below--below the sea in a man built "bubble" where the air is clean and they are fated to live long lives. But this society is completely dependent upon those that remain above, on the earth. Because of that, each year a new group of teens from Atlantia gets to choose life above or life below.
Rio has always dreamed of going above and her sister Bay was always meant for below. But only one can go above and Bay surprises everyone by making the choice.
Rio must come to terms with Bay's decision, attempt to learn more about her mother's mysterious death and find away to join her sister above.
Atlantia is first portrayed as a beautiful paradise, but as Rio discovers more and more of the truth, the decay of Atlantia becomes evident.