"Primogenitor"

Hundreds of years after civilization as we know it has collapsed after a wave of natural disasters, and the United States is ousted by the hierarchical, elitist Ascendancy, a young woman fights for survival in what was once the American Southwest. But Maisie finds herself over her head when she's brought to the heart of the Ascendancy for a mysterious set of experiments. But one thing's for certain: she won't go down without a fight.