The Mermaid Queen's Revenge

Lucia is the princess of the undersea kingdom of Dinelidia, but her childhood ended the night she watched her uncle kill her parents to seize the throne. A blow to the head wiped away her memories, and when a friend and a hotel manager betrayed her and pushed her into the sea, she seemed lost for good. Nereo, a merman, pulled her from the water, returned her memories and her magical tail, and proposed a plan to take back the kingdom together. As they return to the marine realm, Lucia must escape the assassin her uncle has sent after her and find out whether she can rise as the ocean's rightful queen.