The boat Black Whale III sails into the Bermuda Triangle with the Marvin family aboard, intending to search for the remains of Atlantis. Along the way they discover a doll floating in the water, which Diana Marvin—the family's youngest daughter—takes as her own. Diana appears to become possessed by the doll, and starts saying that everyone will die, and telling people the order they will die in. She also locks the ship's cook in the freezer, who almost dies before he is freed. One night, the ship follows a Fresnel lens signaling an SOS even though nothing appears on the radar. They abandon the search after the signal identifies itself as a ship that was lost years ago.