The nightmares of Paul Marsh (Ezra Godden), a successful businessman, are haunted by a mermaid that neither he nor his beautiful girlfriend, Barbara (Raquel Merono), can figure out. While on a boating vacation off the Spanish shore, a sudden storm sends their sailboat crashing into the rocks, causing Paul and Barbara to paddle to the nearby fishing village for help. But the village is inhabited by a race of people who are half-human/half-fish, and the time has come for them to sacrifice humans to their monstrous leader, Dagon. Not only that, but Paul's nightmares become horrifying reality when he encounters beautiful and passionate Uxia (Macarena Gomez), the mermaid of his visions, and boy does she have a surprise for him besides the double tentacles under her skirt.