For three months the citizens of the ancient Grecian city state of Thenis have been holding off the attacking forces of Praximedes, the power-mad ruler of Seronikos. In an effort to avoid more bloodshed, it is agreed that the battle will be decided by a private combat between the leading warrior of each side. Aided by Candia, his seductive mistress, Praximedes persuades Atlas, ...
The opening shot is of a young couple (Gail Ganley and Ralph Reed) in a sports car necking. She excuses herself and the boy drives off. The girl is approached by a man carrying a silver briefcase. He removes his sunglasses and she screams and collapses on the lawn. The man removes a rubber hose and needle and attaches it to her neck and empties her blood into vials in his case....
A series of mysterious aquatic attacks indicate the presence of some huge, previously unknown giant species of shark that has risen to the surface and is preying on tourists, fishermen, researchers, etc. A local beachcomber and scam artist, Sullivan, will have to put out to sea to defeat it.