Synopsis

The chapter details how a vast underground tunnel network was built to facilitate trade and energy distribution, powered by refined demon cores called energy crystals. It explains the societal dependence on these crystals and the devastating consequences of a city's supply being cut off. Later, the group encounters a severely injured warrior who reveals that Pether City has fallen to a demonic wave and triggered its abandonment siren, signaling the death of all its defenders. This leads to the realization of a potential catastrophe.