As the Fourth Age, in which the Lord of Light reigns supreme over the world, descends, the dark creatures are hunted down like stray dogs by the Church of Light.

The earth, the sky, and the sea are no longer places where dark creatures can live.

Only underground do they have a glimmer of hope.

However, the Church of Light swept away the last heretical empire in the land illuminated by the light.

A blade called Light was aimed at the underground world.

Faced with the Holy See's will to purify the entire world, the bone dragon Myriel is very flustered.