In a post-apocalyptic world, Layla has lived her whole life within the safety of the Redoubt—one of humanity’s final strongholds. When her father falls gravely ill and no medicine within the walls can save him, Layla must risk everything. To find a cure, she must endure brutal trials to become a Crosser—one of the few trained to survive the deadly wastelands beyond, where monstrous feeders lurk in the shadows.