In order to stop Jiordal from attacking the surface, the dome that covered the underground world was turned into an eternal existence through the power of the Sword of the Almighty. But once the dome was removed from the order of the world, earthrain began to fall, threatening to destroy all life in the underground world.

To prevent such tragedy, Anos and his followers head towards one of the three major nations of the underground world: Agatha, the land of knights ruled by an all-seeing prophet. There, they encounter a draconid fated to be sacrificed to the dragons—dragons that consume enough sources give birth to "dragonborn." What will happen when Anos and everyone meet these dragonborn meant to support the entire underground world?

The story continues in volume 7, Agatha Prophecy Arc!