A storm brought the girl Peggy and the little merman Dylan from the deep sea to Reynisfjara Beach. An encounter transcending species carved an eternal vow in both their hearts. However, Dylan was immediately taken away by a mysterious organization, prompting Peggy to dedicate herself to marine research, swearing to find her friend. Under the guidance of the Cassiopeians, Peggy gradually uncovered the truth: Merfolk are the descendants of ancient humans who stayed on Earth, living in a Golden Kingdom on the seabed. However, greedy business tycoons coveted the rare Orichalcum and the value of the merfolk, launching a cruel plunder against them, which led Peggy to make the decision to bring down the financial syndicates. This is an epic blending sci-fi and emotion, telling a moving story about love, redemption, and guardianship. Although their reunion came only at death, this love ultimately awakened the conscience of the world, allowing a lost civilization to be reborn.