In the mechanical city "Helheim" shrouded in black fog all year round, the Old God Church uses steam and gears to rule the lower class civilians. Ash, a young scavenger, accidentally dug out a still-beating mechanical heart while exploring the ruins. This heart not only gave him the forbidden power to manipulate metal, but also made him the prey of the Church's Inquisition. During his escape and resistance, Ash gradually discovered that the city's power source actually hid a bloody secret that could subvert the entire world.
