In the Essenland continent where steam and gears are intertwined, a towering mechanical tower "The Spine of Uruk" runs through the sky and the earth. It is said that the "Time Core" on the top of the tower controls the time flow rate and memory storage of the entire world. The ground world is composed of gear-driven city-states, with the roar of steam engines echoing in every corner; the sky city "Novalu" is suspended in the clouds, relying on anti-gravity cores to maintain balance, and the residents of the city control a more advanced mechanical civilization. As a special profession that connects the two worlds, gear restorers are responsible for maintaining the operation of gears on each floor of the giant tower, ensuring the orderly storage of human memory and the stable flow of time. However, in recent years, the giant tower has frequently experienced gear failures, and memory fragments have begun to become chaotic. Until one day, the City in the Sky sent a mysterious invitation to the ground.
