Tolia, amateur treasure hunter, sails the Caribbean until her sailboat is confiscated during a planetary shift, leaving her to protect her injured younger sister. Tolia discovers a jeweled nautilus which she plans to sell to help her ailing sister. The sisters barely manage to escape their captors only to be rescued by a crew plagued by a curse against treasure hunters. Meanwhile, the mermaids are outraged at the theft of their jeweled nautilus and set out to destroy Tolia unless she returns it before the next full moon. The lure of a dangerous love distracts her from accomplishing her quest. Her disrespect of Caribbean magic places those she values most at risk unless she finds a way to make restitution with the sea. A swash-buckle romance is brewed with a supernatural adventure, delivering twists and turns to the bitter end.