Dr. Ted Stevens is tasked with investigating a series of mysterious deaths along a coastal area. Upon examination, he discovers radioactive burns on the bodies. Teaming up with marine biologist Professor King and his daughter Lois, Ted's investigation leads him to an underwater lair where they uncover a research project that has gone disastrously wrong. Professor King had developed a device that emits radiation capable of creating a mutated sea monster that is now terrorizing the waters.

As they delve deeper, Ted and Lois face numerous threats from both the creature and various suspicious individuals looking to exploit King's invention for their gain. With time running out and danger closing in, they strive to stop the growing menace while grappling with moral and ethical dilemmas about scientific discovery and its consequences. The story builds towards a climactic confrontation as Ted attempts to neutralize the deadly threat and save everyone caught in its wake.