The invaders come to Earth to create an H-bomb to blast Earth out of orbit so that Mars can take its place.
Security agent Larry Martin, who can fly with an experimental rocket suit, investigates clandestine visits to earth by a Martian spaceship. Meanwhile, villainous Martians conspire with a traitorous atomic scientist to blast earth out of its orbit and replace it with Mars! Can Larry and his cohort Bob Wilson stop the Martians before they complete their dastardly project? Not a zombie in sight!