Dark-tailed siren Siren avenges his twin brother killed by mermaid royals by impersonating him. He sneaks into the forbidden land and forces a mate bond with slumbered ancient sea god Poseidon to borrow divine power. The enraged god falls for Siren’s fake affection and becomes obsessively devoted. Villains expose Siren’s true identity and stir strife, making Poseidon imprison him. When mermaid nobles rebel to seal the god, Siren shields him at the cost of his life. They reconcile, redeem each other, and rule the deep sea side by side.
