In the steam city "Ettelburg", everything follows the precise arrangements of the central giant clock "Heart of Law". The fate of citizens is like the meshing between gears, precise and ruthless. Elias Thorne is a humble "movement calibrator" who possesses a cursed gift: he can see the shimmering golden "thread of cause and effect" between all things and foresee the "inevitability" that is about to happen. When he foresaw that the "heart of law" that maintained the lifeblood of the city was about to collapse due to a tiny flaw, his prediction was regarded as a blasphemy against the perfect order. After being regarded as a "system redundancy" that must be eliminated by the city's highest authority, the "Grand Calibration Officer," Elias must race against time, against the established trajectory of the entire world, to find the line called "choice" that may not exist at all.
