Xie is destined to rule the Alpha kingdom. Born with the power of the moon, Xie is kind-hearted and just, and she is loved by her people. However, not everyone is pleased with Xie's impending reign. Her uncle, Zhang, seeks to overthrow her and use her twin sister, Luo, to make her believe she is the rightful queen. Zhang manipulates Luo, fueling her anger and ambition. As tensions rise, Xie encounters a mysterious stranger, Chang, trapped in the river. Despite the danger, Xie saves Chang, who is a merman. As they grow closer, Xie must navigate the complexities of royal rules, the prophecy, and the people of Alpha's. Meanwhile, Luo becomes increasingly entangled in Zhang's web of deceit. Will she discover the truth about her uncle's intentions and her destiny? Or will the lure of power consume her?