This YA science-fiction adventure traces the quest of teenager Eva through a post global-warming landscape, where water levels have risen to cover some 90% of the globe. In a similar vein as Hugh Howey's Wool or Arthur C. Clarke's Against the Fall of Night, humanity has survived in select pockets, under the Dome in the Arctic and in select "Layers" (underground shelters) formed from previous cities like Toronto, New York, and Rome.
When Eva's dad leaves the Dome (Layer 0), risking his life in search for medicine, she decides to pursue him in a similar quest (to find insulin for her grandmother, and others in the colony) to show she is capable, but her friend Jeff convinces her she needs help preparing for her journey because there is no predicting what she will encounter.
With Lara's and Steve's help, Eva obtains a boat, but eventually sets out alone across the ocean to discover who actually governs her flooded planet. Along the way she obtains help from a blue whale, observes wildlife on the tops of former mountain ranges, and makes her way to other Layers, where (1) she discovers why Layer 0 has been cut off on its own and (2) stumbles upon a rebellion against the CA, the organization that originally saved the human race. Eva discovers how her upbringing in Layer 0 is radically different from what she finds in the other colonies.
As she explores the settlements of those who have survived, she makes friends with a revolutionary named John Smith, who eventually sends her on her way with an escort, Sasha and Eli, two former friends who once competed for the same woman. Eva's movements, though, are monitored by the military, specifically Admiral Sadie, and by the politicians, led by Mr. Perrah. Here the political setup is reminiscent of The Hunger Games.
Push through the exposition in the opening chapters and the familiar YA tropes, and the story should grab you. We want to see what Eva decides and where she will eventually end up. This book ends with several questions unanswered, leaving us to anticipate future adventures in this world.