A nuclear scientist who defected to the U.S. was exposed to nuclear radiation and has only a short time to live has been living in the desert. But agents from his country try to get him to return. Superman stops them but knows there's another agent whom they only by a code number will try to get him. When Clark tells Jimmy and Lois about him they go to see him and because they came in contact with him, they're exposed to the radiation. They decide to flee not knowing they're going into an area where a nuclear device is to be detonated.