Kira Walker has found the cure for RM, but the battle for the survival of humans and Partials is just beginning. Kira has left East Meadow in a desperate search for clues to who she is. That the Partials themselves hold the cure for RM in their blood cannot be a coincidence—it must be part of a larger plan, a plan that involves Kira, a plan that could save both races. Her companions are Afa Demoux, an unhinged drifter and former employee of ParaGen, and Samm and Heron, the Partials who betrayed her and saved her life, the only ones who know her secret. But can she trust them?

Meanwhile, back on Long Island, what's left of humanity is gearing up for war with the Partials, and Marcus knows his only hope is to delay them until Kira returns. But Kira's journey will take her deep into the overgrown wasteland of postapocalyptic America, and Kira and Marcus both will discover that their greatest enemy may be one they didn't even know existed.

The second installment in the pulse-pounding Partials saga is the story of the eleventh hour of humanity's time on Earth, a journey deep into places unknown to discover the means—and even more important, a reason—for our survival.