The Map of Bones by Francesca Haig

"Book Two in the critically acclaimed The Fire Sermon trilogy--The Hunger Games meets Cormac McCarthy's The Road in this richly imagined post-apocalyptic series by award-winning poet Francesca Haig. Four hundred years in the future, the Earth has turned primitive following a nuclear fire that has laid waste to civilization and nature. Though the radiation fallout has ended, for some unknowable reason every person is born with a twin. Of each pair, one is an Alpha--physically perfect in every way; and the other an Omega--burdened with deformity, small or large. With the Council ruling an apartheid-like society, Omegas are branded and ostracized while the Alphas have gathered the world's sparse resources for themselves. Though proclaiming their superiority, for all their effort, Alphas cannot escape one harsh fact: whenever one twin dies, so does the other. Cass is a rare Omega, one burdened with psychic foresight. While her twin, Zach, gains power on the Alpha Council, she dares to dream the most dangerous dream of all: equality. For daring to envision a world in which Alphas and Omegas live side-by-side as equals, both the Council and the Resistance have her in their sights"-