Perfect Ruin by Lauren Destefano.
High above our world, ”the ground,” is Internment. It was created by the god of the sky, who thinking the first humans were too intelligent to waste saved them when the god of the ground was intent on destroying them. Over the generations internment became a well structured, well guarded machine. The mass of ground lying in the sky is home to hundreds of people, all working pleasantly with little to no questioning about the world they left behind. But they can’t simply forget what was below them. Talk of the ground is natural, but thoughts of going to the ground are declared irrational, and regarded as treason to the king. Morgan Stockhour knows this for certain. Her older brother Lex was a jumper, one who was simply not content with the knowledge handed to them in textbooks. Morgan can plainly see by her brother’s ”incident” what the temptation of the edge can do to you. But that doesn’t stop her. Destefano’s writing is astonishing, engraving the events and images into your heart. Through every page I was tantalized, holding my breath, like I was one of her character’s living out Internets’ fate. I highly recommend it and hope that it brings it’s future readers as much joy as it did me.