This incredibly convoluted thriller has Hopkins on an underwater search to stop a mysterious gang of gold bullion pirates. Ordered to investigate the situation by his superior Morley, Hopkins and his assistant Redgrave pose as marine biologists in a Scottish coastal town. The area has been
shaken by a number of unexplained murders believed to have been engineered by the wealthy Hawkins, who lives on a luxurious yacht with "wife" Delon (real-life ex-wife of Alain Delon) and advisor Mayne. Hopkins spends a great deal of his time investigating the ocean floor until he finds a cave
hidden away under a cliffside castle. In the meantime, Redgrave is mysteriously drowned,...