Zhang Sean checks himself into a psychiatric hospital, convinced he's infected—not by a disease, but by something far more sinister. He sees monsters where others see people, hears whispers no one else can hear, and feels a darkness crawling beneath his skin. When a brutal murder and strange "patients" with terrifying abnormalities begin to surface, Sean realizes he's trapped in a reality where sanity is a luxury—and survival might mean embracing the madness.