Russian scientist Joseph Javorsky is looking to defect to the West and has made it to Nevada in hopes of meeting up with American representatives. Pursued by Soviet agents hoping to prevent his defection, Javorsky is forced to enter into a restricted atomic bomb test range in hopes of shaking off the agents. Unfortunately, an atomic test occurs while Javorsky is on the test range and he is bombarded by intense radiation. Transformed by the exposure to the radiation, Javorsky becomes a hulking unstoppable menace bent upon destruction.