Juniper Unraveling by Keri Lake

Papa says everyone has a story that deserves to be told.
Most begin years ago, after the second bomb hit, unearthing a deadly contagion that divided the population into the pure, the infected, and the Ragers.
Many recount the moment we rose up from the ashes and started anew.
Others tell of the day we built a wall to keep them out.
For some, they’re nothing more than the vestiges left behind—a simple name carved into the knotty bark of a Juniper tree.
My story begins with a boy. A mute, from the other side of the wall, known only as Six, who touched my heart in ways that words never could, and gave me the courage to face my darkest truth.