Soren Daggett is an elite wilderness Search and Rescue tracker accustomed to the world's most unforgiving environments. But when an anonymous client hires him to locate a missing extreme-sports athlete in a blindingly white, massive salt flat spanning thousands of square miles, Soren steps into an inescapable nightmare. He finds his target in the open desert, walking continuously in mathematically perfect circles, screaming that if he stops, he will die. When Soren tackles him to force him to rest, the athlete's heart instantly stops beating. The madness is not psychological; it is physiological. Suddenly struck in the neck by a micro-syringe dart fired from a drone, Soren is injected with an experimental, lethal synthetic neuro-stimulant. His own heart has been rewired: if his walking pace drops below three miles per hour, his heart will seize. His tormentor is a rogue aerospace cardiologist using the infinite desert as a laboratory to test human endurance, casually observing Soren's biometric breakdown from the comfort of a climate-controlled RV two miles behind. Forced into an agonizing 48-hour death march across a landscape with zero cover and absolutely nowhere to hide, Soren's organs begin to fail. He cannot outrun the RV, and he cannot out-walk the toxin. To survive the limitless white wasteland, he must make a desperate, agonizing choice to weaponize the freezing desert night against his stalker—even if it means risking his own heart stopping forever.