While out fishing one morning, Andy and Opie happen upon a stranger out by the lake. As Andy and Opie head off to the lake, the stranger helps himself to the bag of sandwiches they left in the squad car and walks off without a care in the world!
A little while later, Andy returns to the courthouse and finds that Barney has arrested the stranger for vagrancy and loitering. Although he hasn't necessarily done anything wrong, Barney suspects that he's up to no good and a drifter or hobo, preying on Mayberry in search of a few free meals. Andy reveals that he's already met the stranger, whose name is David Browne. Andy decides that since Mr. Browne has no money and no visible means of support, he will give him a job trimming the hedges around his house. Mr. Browne seems to happily agree, much to Barney's dismay.
The next morning Mr. Browne is sitting with Opie on the front porch, seemingly getting ready to trim the hedges as he promised. After a bit of creative contemplation, Mr. Browne decides that is would be best if he went fishing, his logic being that fish were meant to be caught and eaten and his was his responsibility as a human being to both catch and eat fish. He drops his shears and is off to the lake. Opie considers Mr. Browns logic, ditches his school books beneath a bush and follows him to the lake.
When Barney catches Opie sneaking into the courthouse to get a fishing pole, he confronts Andy with the fact that David Browne is a bad influence on Opie. Andy is reluctant to jump to that conclusion. The next day Andy finds out that Opie has been hanging out with Mr. Browne again and even had lunch with him, a chicken that the drifter helped himself to. Andy realized that Opie has come to idealize the vagabond drifter and his carefree, live by your wits life Not only does David Browne spend his days fishing and relaxing, he seems to eat rather well for a man with no means of support.
Rather than allow Barney to arrest him, Andy sets out to have a talk with Mr. Brown and ask him to stay away from Opie. During the conversation Mr. Browne pointedly asks Andy why he doesn't let Opie decide for himself what lifehe'd choose. Andy explains that with children, a parent can't simply let them choose lest they pick the first thing that comes along wrapped in shiny ribbons – in other words, the hobo lifeseems to be all fun and games to a child even though they both know it's not. Andy tells David Browne that he's no longer fit company for Opie. When the drifter suggests his problem is solved, Andy replies, "No Mr. Browne. That boy thinks just about everything you do is perfect. So my problem is just beginning."
A short while later Barney hauls David Browne into the courthouse again, this time for purse snatching. Barney has caught the drifter red handed with Aunt Bee's pocketbook. When Opie realizes what Mr. Browne has done, stealing from his own Aunt, from the money she uses to buy food, he is heartbroken. He returns the homemade fish lure that Mr. Browne gave him and walks dejectedly out of the courthouse. When Opie leaves Andy confronts Mr. Browne with the fact that the purse he supposedly stole was, in fact, one that Aunt Bee threw away. As Andy opens the cell to release the prisoner a train whistle can be heard. Andy suggests that Mr. Brown be on the train and out of Mayberry forever. When Andy tries to thank the drifter for setting things right, Mr. Browne just smiles and says "Like you said sheriff, I got a train to catch," and walks off.