Toxic

Long ago, a volcano called Yellowstone erupted and blocked out the sun, creating a never ending winter. Before the air became too toxic to survive on, humans built and moved into greenhouses. Leading these civilizations are the Greens, and our species happily lives on, if you live inside. If anyone over the age of fifteen commits a crime, they are sent outside to live in posts and doom their descendants to a life in an eternal wasteland. We are called postees, and life is not happy. Personally, I have a tendency to wander off post and to pre-record ruins and wonder why it appears as if everyone was massacred.
Recently a terror organization has been causing havoc for the Greens and tenders, but is it for the right cause? Is it bigger than the rebellion it sparks? What are they both hiding? Everybody has questions, these are just mine.