Paul Stanton has talked his son Billy into being sent to California to join his mother, Sally, and her old high school sweetheart (and current new boyfriend) Mike who are going into Arizona. Passing through Death Valley, they discover it is the new territory of a cowboy serial killer (who wearing a hat and a neckerchief to hide his identity) and his equally demented twin. Both have just done away with a teenage couple at an abandoned gold mine. Billy, stretching his legs, stumbles across their camper. Somehow overlooking the carnage, he comes across a frog pendant, which he steals. Its owner returns to find his trinket gone and pursues.