The plot: Ken (Chiba) and Jenny (Neal) are reporters covering a navy demonstration of a new guided torpedo. They are a really cute couple who can't resist making goo-goo eyes at each other. The torpedo test fails, but Jenny sees a Sleestak-like creature pass one of the underwater cameras. The navy does not believe her, but a doting Ken does, and the two go diving into the waters off Japan to investigate. Jenny finds the creature but loses the camera (as Hooper did in "Jaws") as she swims to the surface in total fright. The navy still does not believe her, without seeing photographic evidence. The ever fawning Ken takes her out for a second dive, perhaps because she looks great in the tight, red diving suit. This time they find an underwater cave, and of course swim into it. Shortly after their arrival, several of these aqua-creatures capture them.
Our cute captives are brought to the evil Dr. Moore who has one of the best deviant laughs in movie history. He tells our love-struck duo that he is bent on world domination and the creatures are former humans which he is able to convert to his drones. He can control them with super-sonic sound from his machine. It is a complicated machine with one dial that can be turned to either "Work" or "Fight." Moore gives Ken and Barbie....I mean Jenny, a chance to join his plot to conquer the world. They refuse. Moore adds in this zinger; while drooling at Jenny, he informs them that after converting humans to his creatures, they are devoid of any sexuality. NO!!!!! Then he has Jenny prepped for conversion.
Will Ken be able to save Jenny from a fate worse than neutering? Will our amorous duo find the proverbial self-destruct button and find the proverbial escape hatch? Will the navy get with the program and mount a rescue attempt? This film is a lot of fun. Seeing a young Sonny Chiba is cool, and his co-star is the perfect damsel put in distress. Bide your time before the new "Godzilla" comes out in May, and see "The Terror Beneath the Sea."