Cora, a mermaid who lives in a magical sea cavern named Pouraka falls in love with a handsome merman, Tas, who is fleeing with his clan from humans seeking to capture them. Trouble follows these refugees when an unscrupulous oil rigger's son discovers the rich aquatic life Barnacle Bay harbors. Mermaids, instead of dolphins, become his prey.

When Tas is captured and waits to be transported to a marine amusement park, Cora must find a way to free him.