Under the sea, at a depth of four thousand meters, there is a world without light.
There's no phosphorescent algae living in this stretch of ocean, and without this sole source of light at the bottom of the sea, the entire area is shrouded in absolute darkness. There's nothing to see, no sound to hear, no scent to smell. The only thing their skin touches is the cold seawater, and the only taste in their mouth is the salt of the sea. Deprived of all senses of the outer world, they can't see the path, unable to discern the direction. After leaving the Sea Race behind, the power of the deep-sea world finally becomes evident. The pain they never experienced before descends—all-consuming fear and oppression turn into endless waves, constantly battering the girls' minds.
