Olds: Louis Edmonds (Gunther Stiller), Albert Dekker (Walter Ludeker).
U.S. Intelligence assigns Jill Parsons to investigate the mysterious deaths of two secret agents in the Caribbean. The agency fears that the deaths may indicate danger to a meeting of foreign ministers scheduled to be held aboard an aircraft carrier in the area. Jill infiltrates a local skindiving competition to be held off a charter boat belonging to young Pete Barker. Meanwhile, the activities of the skindivers are being carefully observed by enemy agent Walter Ludeker, who has been laying highly explosive equipment across the ocean beds. In an attempt to learn if a U. S. agent is among the divers, he persuades his nephew Larry to enter the competition. Though another woman, Samantha, is wrongly suspected and kidnaped, Ludeker later realizes that it is Jill he wants, and he abducts her also. When U. S. Intelligence learns of Jill’s disappearance, they raid Ludeker’s stronghold, rescue the two women, and destroy the network of underwater explosives. With the completion of her assignment, Jill is free to reveal her romantic interest in Pete. TCM.