In the distant waters of the South Sea, around the unnamed islets surrounding Odell Reef.
A world completely encircled by water.
This was a hidden oceanic Blue Hole. At the center of the reef cluster lay a sudden, deeply sunken stretch of dark sea. It was filled with seawater, yet deep within its mouth lay concealed drainage channels.
At regular intervals, the water in the Blue Hole would be completely drained away, until the rising tide brought by the ebb and flow of the sea filled it once more.
The entrance to Redwood Base was located at the top of a Z-shaped opening at the bottom of the Blue Hole. A peculiar wall of air at the entrance kept out the seawater, while the drain at the bottom of the Blue Hole likely led directly to the cooling zone. In other words, this was a secret entrance that could never be filled, yet was always blocked by the deep-sea waters.
Of course, to the Pre-Epoch Civilization, this was probably no more than an elegant little spectacle.
But now, it was incomparably well hidden, almost impossible to discover.
The surviving members of the guard squad back then had probably been swept into this region by the Great Storm, then happened to enter the opening while the Blue Hole was draining.
Everyone stood at the outermost edge of the islet, greedily breathing in the fresh natural air—although the heavens and earth were filled with dark clouds and curtains of rain, it was still far better than the stifling underground ruins reeking of insects.
"Finally, finally, we're out—next, we just need to contact Uncle Aels..."
At last, Isengard let out a breath of relief. He had kept his nerves taut the entire time, doing his utmost not to become a burden to the