Mining Area Fortress, Joint Operation

The so-called Redstone City mining area lay in a gray-blue stretch of sea spanning thousands of kilometers, artificially designated as a no-fly zone.

Viewed from high above, this sea looked little different from any ordinary open water. But once one's gaze dropped beneath the surface, an entirely different scene came into view.

In the shallow waters roughly ninety to one hundred fifty meters below the surface, vast coral cultivation racks resembled submerged terraced fields, spreading tier by tier along the gentle slope of the seafloor.

Each cultivation rack was an enormous composite framework, built with spiritwood and rune-reinforced alloy as its skeleton, with tens of thousands of coral beds hanging vertically in layers.

The coral in those beds was not the rough hard shell found on ordinary reefs. It was translucent from end to end, like a glassy forest in the deep sea, stretching east to west and south to north, with no end in sight.

Nearly sixty percent of the seabed beneath this thousand-kilometer expanse was covered by such cultivation racks. Every three li, an underwater monitoring tower stood amid the coral groves. The rune lamps atop the towers emitted spiritual ripples at fixed intervals, monitoring water quality, temperature, spiritual concentration, and coral growth.

Among these coral cultivation racks, only one Mother Coral might appear for every several hundred thousand ordinary corals. It was several times thicker than normal coral, its branches forming a peculiar spiral shape.

As it grew, the Mother Coral continuously absorbed free spiritual energy from the seawater and deposited it within itself, slowly condensing clusters of rice-grain-sized crystals. Once mature, these crystal clusters were carefully stripped away and polished by specialists, eventually becoming the core raw material for Energy Stones.

At the edge of this cultivation sea, an offshore platform pieced together from rune-reinforced panels