After the last Great War, the world is covered by a black forest inhabited by fire demons. The survivors of the war, living in small areas protected by barriers, have been infected by a pathogen that causes them to spontaneously combust in the presence of ordinary fire. The only safe "fire", the only source of light and heat they can use, comes from the demons captured in the forest. And when the paths of a country girl and a young man from the capital cross, a new destiny opens up for them.
When the world is invaded by supernatural creatures who condemn people to hell, a religious group claims to be divine justice.