The most dangerous secret in the world isn't a weapon. It's an answer.Nathan Brooks is a mathematician who has optimized every variable in his life - career, routine, productivity - and still can't say why none of it feels like enough. Then he finds his mentor dead in a locked office, two words written in blood on the floor: THE EQUATION. The drawers are empty. The files are gone. And the brass key in Nathan's pocket is the only thing the killers d...