Three months after her mother's death, twelve-year-old Kela is still grieving and feels haunted by the last argument she had with her mother. But when Kela and her friend Lissy stumble across an ancient-looking comb in a coral cave, Kela finds herself coming face-to-face with the mermaid Ophidia. Ophidia's magic requires that she make a bargain with whoever finds her comb in exchange for a wish. Kela's greatest wish is for her mother to be alive again, but she soon learns this wish may come at much too high a cost.
