The Earth is split into three kingdoms. One resides in the sky, one lies beneath the waves, and one remains on the surface. Ruled by a tyrant, life on the surface is oppressive and littered with human misery and poverty. People are brutalized in the streets and hope seems like a long forgotten ideal. For fifteen year-old Sam Cutter, that's enough reason to risk everything and head for the Sky Nation. Anybody caught leaving disappears, never to be heard from again. If Sam can escape, he'll be the first to make it in ten years. Still, Sam is determined that nothing will stop him. Heading into the unknown with little more than a bag slung across his back, Sam turns and waves goodbye to life on the surface before sneaking onto a cargo ship and leaving the world he knows behind. Sam's journey takes him on an adventure filled with unexpected turns as he is abruptly thrown into the middle of a war, forced to choose a side, and fight to stay alive. Sam learns to trust his instincts and that he may be more important in this struggle than anyone could have ever known.