When a stranger gets off the bus from New York City, the folks in Mayberry are naturally curious. When he strolls into the barbershop - calling everyone by name and knowing things that no stranger should know - their suspicions go into overdrive, especially since nobody knows who he is. In fact, Ed Sawyer's knowledge of the goings-on in Mayberry is uncanny. Soon, as a result, he's accused of being everything from a foreign spy to a space alien - or worse! - and his friendly attempts to fit in and settle down are coldly rejected.
Andy, on the other hand, seems to be the only one in town unwilling to judge Ed until he knows the facts. After a particularly curious encounter twixt Ed and Lucy Matthews, the woman he loves - whom he's never even met! - Ed asks Andy for help and explains how Mayberry came to be his "hometown", revealing that he's a loaner with no family and no real home. It seems that, in the Army, he befriended a young man from Mayberry and loved the stories he told about "back home" so much that he began to take the town newspaper and tell folks that he was from Mayberry.
As Andy is calling the town's newspaper to explain things, Ed is confronted by a frightened, angry crowd who want to run him out of town. Andy steps in - telling Ed's story and delivering a stern lecture about how to treat people who may appear to be a little different. Hearing how their "friendly" nature caused a total stranger to embrace them, the "mob" backs down and warmly welcomes their new neighbor to Mayberry.