 Andy receives a letter from an ex-con that he shot in the leg, years ago, in a gas station robbery attempt. He has lost most of the function of that leg. The ex-con writes that he is coming to Mayberry to set things straight. Barney assumes the worst. When Andy won t take a vacation or at least carry a gun, Barney deputizes Gomer and Otis to keep watch and protect Andy 24 hours a day.