Holsworthy Mark Show

Intelligent, parasitic extraterrestrials that resemble Terran rocks, intent on enslaving the human race, find a hideout in geologist Dr. Jonas Temple's lab. Although undetected by ordinary humans, physician Dr. Paul Cameron, who has a surgically implanted metal plate in his skull, is able to "hear" the alien "rocks" communicate with each other. Aware that he can hear them (while referring to Paul as "the listener"), they realize he is a threat, and compel him to kill himself by jumping from the lab window. At the last moment he is saved when his wife, Laurie, Dr. Temple's assistant, returns to the lab, breaking the aliens' mind control. Thinking he is going insane, Paul takes an impulsive vacation to Mexico with Laurie to help clear his troubled mind. Dr. Temple, now controlled by one of the "rocks" after it enters his body, pursues them. In Mexico, Laurie becomes possessed after Dr. Temple finds her alone in the remote desert cabin that she and Paul had r