"The Sea Hornet" was a merchant ship sunk, supposedly by a torpedo, less than a mile off the California Coast during World War Two. Six years later when his buddy is killed, attempting to blow up the sunken ship, on the orders of Suntan Radford and Tony Sullivan, deep-sea diver "Gunner" McNeil has his suspicions aroused... especially since Suntan is the daughter of the ship's captain that died when the ship sunk, and Sullivan was a crew member. Plus the fact the ship had over a million dollars in cash on board. During the course of his investigation, he becomes romantically involved with Ginger Sullivan.