Cleve Ritchie has found the lost Barcelona Treasure, and plans to share it with the entire town. Cleve lives in town with his grandmother, Granny Ritchie, who is paralyzed by a stroke and cannot talk. Doctor Payton has his girlfriend/nurse, Stella Watkins, take a job as full time caregiver for Granny so that he can keep track of Cleve's search for the treasure. Cleve makes a map showing the treasure's location, and The Ranger and Tonto have to save Cleve from Dr. Payton's two henchmen. He secures the map in the safe in his house. Later, Granny witnesses Stella open the safe and give the map to the two henchmen, but then they kill her when she wants a bigger share. Doctor Payton thinks he's safe as Granny can't talk, but The Ranger devises a system where one blink of the eyes means yes and two blinks mean no. By asking Granny questions, The Ranger uncovers then entire plot. Now he, Tonto, and Cleve, have to protect Granny and figure out a plan to trap the bad guys, especially the seemingly respectable Doctor Payton.
Christine Larson plays Stella. In the 1990's an unauthorized biography of President Ronald Reagan claimed that Christine turned down a marriage proposal from Reagan, and that the two of them had an affair after Reagan married Nancy Davis. Christine had died young in 1973.
Mira McKinney plays Granny. Her father was a well known lawyer who came up with the idea of dividing the laws of New York into small books which could be carried easily by lawyers into court. His system is still used to this day. When Mira was a girl, the McKinneys lived on Long Island and were neighbors of the Theodore Roosevelt family. Mira and her brother played with the Roosevelt children.