The film opens with a dream sequence in which stock market tycoon Paul Marsh discovers a mermaid with razor sharp teeth while scuba diving into a carven pit. Paul awakes on a boat off the shores of Spain, where he is vacationing with his girlfriend, Barbara, and their friends Vicki and Howard

• Dagon
• Stuart Gordon
• Ezra Godden
• Francisco Rabal
• Raquel Meroño