Granted this show has one of the most unlikeliest premises of all the "Barney Returns to Mayberry" shows. However, despite this Knotts return for a moment re-energizes Griffith and the entire show. All of a sudden there's a chemistry and an energy that is sorely missing in most of the season 8 shows.
At this point Floyd, Gomer, Otis, the Darlings and Ernest T Bass as well as Barney (and many season 1-5 writers!) were all gone from the show and it missed the manic energy and comic creativeness of the early years. In the "Star Trek" episode "City on the Edge of Forever" Captain Kirk strolls with Edith (Joan Collins) down the main street of Mayberry (passing the courthouse and Floyd's barber shop!) and here the Enterprise's Dr. Dehner (Paul Fix) appears as the homeowner whose house barney hopes to use. He's great as a crotchity old guy!