The world has experienced an "annihilation-level explosion." District 7, once the federal technology center, has now become a radiation-ravaged ruin, with distorted buildings and mutated organisms. Radiation pollution has caused drastic changes in the surface environment. The extinction of old-era creatures has reappeared in mutated forms. Human beings are struggling to survive in the ruins, forming a social form centered on survival. Luminous spores, the "earth's immune system", will appear when radiation exceeds standards, clearing away the polluted old world and nurturing new life; ancient symbols, memory inheritance, etc. On the surface of the energy core hint at the existence of ancient civilizations or mysterious forces beyond current understanding.
