In a post-modern civilization reverted back to medieval life, awakened dragons ravage humanity and render gunpowder and rocket fuel inert. Humans are no longer the apex predator, as they struggle to survive underground and within the concrete ruins of the past. A lone mercenary, offering his services to make a living, travels between besieged villages and settlements with a shield that protects against all dragonfire "Aegis" and his mighty Dragon-slaying Sword "Balmung".