One lazy Sunday afternoon, Lisa calls in to an unpopular public radio station and wins tickets for four to a movie called Kosovo Autumn; she is the only person in Springfield willing to listen to discussions about obscure Peruvian banjo music. The film, a parody on several Eastern European dramas, is subtitled (the original language being Albanian).
Since Lisa only has four tickets, Homer leaves baby Maggie with his neighbor, Ned Flanders, after barging into his house to find him in the midst of bathing. Friendly as always, Ned doesn’t mind Homer’s intrusion and agrees to babysit without charge. When the Simpson family returns, Marge picks up Maggie and hastily offers to pay Ned for his troubles. He politely refuses but admits that a little extra cash in his life would not hurt, seeing as the giant retail store Left-Mart is threatening his business. Kindly, Marge suggests that he rent out one of the rooms to someone. He agrees, giving the room to a pair of girls from the community college named Katya and Vicki.
Taking advantage of his trusting nature, the two use their room as a staging area for a pornographic website, sexyslumberparty.com which shows them spanking each other with a picture of Rod. Bart and Milhouse come across a banner ad for it while searching Ask Jeeves and share their discovery with Homer. Finding the whole thing extremely amusing, Homer proceeds to spread the word, which spreads through their town like wildfire. A self-righteous Marge, however, soon discovers both father and son viewing the pornographic material and demands Homer tell Ned everything. Horrified at both the town’s mockery and Homer’s betrayal after working so hard to be kind to them, Ned promptly leaves town, moving to Humbleton, Pennsylvania, home of the charming porcelain “Humble figurines” (a parody of Hummel figurines), which he collects.
Marge and Lisa, who are angry at Homer for driving away a great neighbor like Ned, tell him to be on his best behavior with the people who are going to arrive next door. Clay “Coach Clay” Roberts, the new neighbor who moves into Ned’s house, proceeds to bully, mock, and physically attack Homer at every opportunity, berating him for his weight and lack of strength. Homer tries to be a good neighbor to Coach Clay, but it is a fruitless gesture. Coach Clay cuts down Ned’s pine trees, which fall into the Simpsons’ yard and cut their cable, and siphons gas from Homer’s car (a parallel to Homer often stealing valuables from Ned).
Meanwhile, Ned originally finds the pseudo-Germanic town of Humbleton to be everything he ever dreamed. The townspeople are friendly to a fault; the houses are charming and freshly painted. It seems to be the ultimate idyllic utopia. However, when applying for a job at the Humbleton Figurine Workshop, the manager’s only request is for him to his shave his mustache, declaring it “hippie-ish” and distracting. Ned briefly considers it but soon decides his “nose neighbor” is more important than the townspeople's opinions (pro-life Ned ironically declares that "It's my body and my choice!"), who immediately shun him.
Marge becomes irritated with Coach Clay’s rap music and brash behavior and forces Homer to try and fix what he did. Homer then drives to Pennsylvania and pleads with Ned to return, who, upon seeing the judgmental faces of the Humbleton residents all glaring at him, agrees. Unfortunately, Coach Clay doesn’t want to leave the house, despite Ned pointing out that the $200,000 check bounced and, legally, he still owns the property. However, he is persuaded once Ned overpowers him by sheer force, causing him to beg for mercy. Homer then hits Clay over the head with a chair anyway, inexplicably declaring that it was “what heroes do.”
A few hours later, Homer obtains a pipe organ and places it in Ned’s backyard for a welcome-home party, which several Springfield residents attend. At first Ned has doubts about it, believing that Homer stole it from the church (which he did, based on the several bent pipes and Homer’s guilty expression ), but Homer tells him he’ll return it after the party. Ned is happy at the party, but it doesn't take long before Homer starts getting irritated at his old-new neighbor, and both Marge and Lisa have here-we-go-again looks on their faces...