Poseidon dispatches Arthur, a powerful warrior, to return to the Merfolk Kingdom eighteen years after being cast out and secure the throne. As Arthur arrives, he encounters warriors from the current royal house, House Sterling, who are fiercely loyal. The situation escalates when they spot a human intruder in their waters and demand his immediate execution, invoking the Merfolk Edict that mandates death for any human found there.
A tailless merman returns to the merfolk kingdom to find his family, questioning their hostility. Princess Elena recounts meeting him, causing her father, the King, to panic over an old prophecy warning that such a being brings doom. Confronted by the King, the merman reveals a family tear-crystal. The Queen recognizes him as her lost son, Valen, but the King orders him expelled, citing the curse. As political enemies surround them, the Queen secretly gives her son a potion to disguise himself, urging him to flee undetected.
Suspecting the Sterling family knows about his origins, the tailless merman Arthur visits their home. His arrival triggers a crisis as his mother, Seraphina, declares her intent to reclaim her son, but other family members, fearing a prophecy, violently oppose her. They argue that his return during the king's election could destroy their house. Arthur is placed under house arrest, with a threat on his life. Later, while sharing a bittersweet birthday moment with Seraphina, where he expresses a wish to find his real mother, intruders arrive for the election. Seraphina urgently warns Arthur to stay hidden, no matter what happens next.
A trial by combat begins to determine the next ruler, with each bloodline sending three champions. Prince Cale, a speed-type merman, eagerly volunteers for the first round. He is immediately confronted by a massive, gravity-wielding opponent who mocks his slender build and threatens him with a hammer. During the brutal clash, an onlooker points out Cale's tail is his weak point, a strategy later echoed by a concerned voice to Princess Elena as she faces the same foe. The opponent tries to goad Elena, but she seizes her moment, countering his taunt with a decisive, lethal strike.
Elena wins a crucial fight but is fatally wounded by a poisoned blade. Her family, House Sterling, declares the sacrifice acceptable for their glory and refuses to intervene as she has only minutes to live. A man named Valen protests, but is silenced and told the family's affairs are not his concern. As Elena lies dying, a woman arrives, comforts her, and reveals herself to be Elena's mother. The episode ends with the shocking revelation of this maternal connection while Elena's life rapidly fades.
Exiled as a tailless omen, Arthur returns as the Sea God to the Merfolk Kingdom that cast him out. His quest to find his birth parents collides with the kingdom's turmoil. After saving Princess Elena, he discovers the cruel superstition that doomed him. Queen Seraphina secretly recognizes her lost son but is bound by duty. When a coup led by Marcos erupts and Elena is mortally wounded, Seraphina's sorrow births a mermaid's tear, unveiling Arthur's royal lineage. To save his mother and the kingdom, the once-scorned outcast must unleash his full divine power and claim his destiny.
Exiled as a tailless omen, Arthur returns as the Sea God to the Merfolk Kingdom that cast him out. His quest to find his birth parents collides with the kingdom's turmoil. After saving Princess Elena, he discovers the cruel superstition that doomed him. Queen Seraphina secretly recognizes her lost son but is bound by duty. When a coup led by Marcos erupts and Elena is mortally wounded, Seraphina's sorrow births a mermaid's tear, unveiling Arthur's royal lineage. To save his mother and the kingdom, the once-scorned outcast must unleash his full divine power and claim his destiny.
Exiled as a tailless omen, Arthur returns as the Sea God to the Merfolk Kingdom that cast him out. His quest to find his birth parents collides with the kingdom's turmoil. After saving Princess Elena, he discovers the cruel superstition that doomed him. Queen Seraphina secretly recognizes her lost son but is bound by duty. When a coup led by Marcos erupts and Elena is mortally wounded, Seraphina's sorrow births a mermaid's tear, unveiling Arthur's royal lineage. To save his mother and the kingdom, the once-scorned outcast must unleash his full divine power and claim his destiny.
Exiled as a tailless omen, Arthur returns as the Sea God to the Merfolk Kingdom that cast him out. His quest to find his birth parents collides with the kingdom's turmoil. After saving Princess Elena, he discovers the cruel superstition that doomed him. Queen Seraphina secretly recognizes her lost son but is bound by duty. When a coup led by Marcos erupts and Elena is mortally wounded, Seraphina's sorrow births a mermaid's tear, unveiling Arthur's royal lineage. To save his mother and the kingdom, the once-scorned outcast must unleash his full divine power and claim his destiny.
Exiled as a tailless omen, Arthur returns as the Sea God to the Merfolk Kingdom that cast him out. His quest to find his birth parents collides with the kingdom's turmoil. After saving Princess Elena, he discovers the cruel superstition that doomed him. Queen Seraphina secretly recognizes her lost son but is bound by duty. When a coup led by Marcos erupts and Elena is mortally wounded, Seraphina's sorrow births a mermaid's tear, unveiling Arthur's royal lineage. To save his mother and the kingdom, the once-scorned outcast must unleash his full divine power and claim his destiny.