In the eternal city of Arcadia, memory is not an illusory past, but an entity that can be extracted, crystallized, and traded - "spiritual dust." It drives the city's splendor and feeds the darkness deep within its foundations. The "pure ones" in the upper city rely on consuming the memories of others to continue their lives, experience emotions, and acquire knowledge, while the "source bodies" in the lower city are reduced to fields being harvested in the midst of day after day labor and forgetfulness. This is a world fueled by souls. And our story begins with a speck of spiritual dust that shouldn't exist, and a scavenger who doesn't remember who he is.