Captain Andrew secures his cruise ship in the safe waters of a tropical island to escape a hurricane. While he and his crew prepare to leave, Andrew gets a visit from a mysterious, handsome merman who convinces him the island may contain a paradise beyond his wildest dreams.

Afterward, Captain Andrew and the crew of the Diamond discover the volcano on El Paradiso, the tropical paradise where Tirnan and the merpeople live, is about to erupt. Suddenly the world's attention is focused on the tiny spec of land.

Can Andrew and his crew race against time to keep the merpeople's presence a secret when scientists and reporters from all over the globe are descending on El Paradiso?