"Aria and Perry, two teens from radically different societies--one highly advanced, the other primitive--hate being dependent on one another until they overcome their prejudices and fall in love, knowing they can't stay together"--
"In their effort to reach the fabled Still Blue, Aria and Perry will have to rescue Cinder, defeat Sable and Hess, and unite the Dwellers and the Outsiders once and for all"--
Hoping to be reunited after months of separation, Aria and Perry are met with hostility by Dweller-resenting Tides before a Aether storm threatens the tribe's existence, forcing Aria to consider leaving Perry to save both their lives.