At just six years old, Nathan made a heartbreaking deal: disappear forever to save his dying mother. Years later, he's a nobody in the poisoned Undercity, struggling to survive while developing an invention that could change millions of lives. But the woman he loves steals his work and dumps him for a rich heir—in front of everyone. What they don't know is that a billionaire in Sky City has spent years searching for her missing son. And the biggest mistake they ever made was underestimating Nathan.
