This is a standalone novel set in the future when earth's surface has become so polluted that all those that live there become ill. There is built an undersea cities like Atlantia. Atlantia is dependant on the 'above'-those who remained above water. The people above send down supplies and keep these cities going. Those who live Below consider themselves incredibly fortunate and lucky. On the sixteenth birthday of a citizen of Atlantia they are given the option to continue living Below or to sacrifice themselves to the Above to assist those Below.
I loved the setting of this book. It reminded me of Atlantis. I loved the way that history would get lost. It's a sad kind of digression that is always so addicting to me. There were so times when I wasn't sure what was going to happen. The characters were not typical YA characters. They would often behave in ways that were much more realistic than usual dystopian fiction. It was refreshing.
I loved this book. I give it four and a half stars and I highly recommend it.