When her mother dies in a heat wave that kills twenty million, Zia León abandons a promising diplomatic career to lead humanitarian aid missions to regions ravaged by drought, wildfires, and sea level rise. What Zia doesn't know is that clandestine forces are gathering around her in pursuit of a colossal secret: someone has hijacked the climate, and the future of human civilization is at stake. To avoid a world war that appears more inevitable every day, Zia must build a coalition of the powerless and attempt the impossible. But success depends on facing the grief that has come to define her life, and rediscovering friendship, family, and what it means to be true to yourself while everything falls apart.