Facing an invasive fleet of lethal deep-sea drones from the ruthless pharmaceutical giant Ambrose Pioneer Biotech, brilliant human strategist Ryan executes a high-stakes gamble—forging a fake dead hybrid specimen using ancient sea-lizard bones and degraded DNA to trick corporate hunters into believing his lethal siren lover, Seraphis , is extinct. After successfully scaring off the biotech empire, Ryan binds his soul to Seraphis through an eternal Symbiosis Contract and follows him into the mysterious Sacred Sea . Yet entering this uncharted aquatic paradise brings new perils: hostile merfolk clans despise land-dwellers, only to be bloodily suppressed by Seraphis’s obsessive dominance—"Shut up, he is my only mate!" As Ryan utilizes human wisdom to cure neurotoxins and save dying reefs, dark secrets surface about why this ancient apex predator crossed frozen oceans eight years ago just to claim him, leaving one tense question: in a world where merfolk possess only half a soul, can a fragile human outsmart the abyss and survive the possessive love of the ocean's deadliest king?
