Top marine biologist Moriarty, obsessed with creating an immortality serum, slaughters Finnian’s merfolk clan and then poses as his savior, imprisoning the survivor in an underground tank. Over three months of fabricated tenderness, he steals Finnian’s scales and dependence. When the truth emerges, Finnian transforms from docile captive into a defiant avenger, risking death to escape. Moriarty’s pathological possessiveness drags him back each time, yet he shields Finnian with his own body when black-market sponsors come to claim the specimen. In the final reversal, Finnian drags Moriarty into a ten-thousand-meter abyssal trench, locking him there forever. This is a dark fable of deception, taming, and role reversal—where cage and keeper constantly shift, and love and hatred fuse into one beneath the crushing depths of the ocean.
