The marine ecologist Nerissa was swept into the sea by a storm during her research expedition and was imprisoned in a deep-sea bone prison by the Sea Witch King Thalos, who bore the blood feud of her people. Using marine restoration technology, she repeatedly rescued injured sea witches; she even sacrificed herself to save Thalos when his old wounds flared up, gradually melting the ice in his heart. Lyra, another female witch from the same clan, harbored jealousy and resentment, repeatedly framing others; meanwhile, her fiancé Kai was exploited by the human capital magnate Adrian, who disguised himself as a benefactor to secretly hunt the sea witches in order to extract their immortal genes. Nerissa navigated between the two factions, gathering evidence of their crimes and exposing their conspiracy, ultimately facilitating peaceful coexistence between humans and sea witches. She let go of everything on land, returned to the deep sea, and stood alongside Thalos, becoming the Queen of the Deep Sea.
