Blood Tide

Neil (Martin Kove) and Sherry Grice (Mary Louise Weller) sail to a Greek island to find Neil's sister, who vanished there, and no one in the village will explain where she went. Frye (James Earl Jones), an adventurer after sunken treasure, has already freed a monster in the water, and the villagers have gone back to offering human sacrifices. The Grices now have to find Neil's sister before the island decides who comes next.