When magical mermaid Sereia saves her sister, she inadvertently overshadows her brother Triton, the rightful heir to the throne. In a bid to secure his position, Triton curses Sereia, transforming her into a human and stripping her of her magic, while warning her that returning to the sea will turn her into a monster. Left for dead, Sereia washes ashore in Atlantis, where a kind merchant with a tragic past helps her build a new life. As she learns more about humans, she begins to question everything she was taught. However, the threat of discovery looms large, as mermaids are hunted for their magic. Sereia must keep her identity secret, even as her feelings for her savior grow. She channels her skills into joining the Atlantean army, striving to become the warrior she always wanted to be. During her training, she learns of a powerful trident hidden in Atlantis, offering a potential path back to the sea. Torn between revenge and love, she faces a dire choice when a friend's life hangs in the balance: risk being burned as a witch or embrace the monster she could become if she returns home. This tale weaves themes of loss, love, and vengeance, exploring the life of one of fairy tales' most notorious villains.
