Near a forest village of hunters and farmers lies a ruin of stone, glass, and steel, shrouded in a mist that blocks the sun and crawling with soulless metal "demons."

From the ruins comes a monster, driven by madness as it burns a great swath of forest. Fearing for the safety of his home, a hunter sets out to the ancient city to slay the beast, yet things are never so simple.

The hunter finds himself with a companion on his journey, and there are others in the old ruins awaiting the arrival of the two. Little known to the simple forest dwellers, the fate of the entire world is bound to their actions in the city of steel.