The commissioner of football is in town to finalize the awarding of a new professional football team to Springfield, but when he gets lost and asks for directions at the Simpson house, Grampa ties him up, leading the commissioner to cancel the team. This results in everybody in town hating Grampa to the point where he tries assisted suicide, but when that doesn't happen, he decides to live life to the fullest, starting with being the toreador at the new football-stadium-turned-bullring.
The commissioner narrows down the choice of the two cities to either Springfield or Los Angeles. L.A. puts forth an anti-Springfield video hosted by Rob Reiner and features a song sung by celebrity impersonators that ends with them singing "Springfield Blows". All the owners decide that Springfield is the lesser of two evils, plus they're sick of L.A getting everything, and the Commissioner awards the new team to Springfield. The town gets "Meltmania" and "Down syndrome" and quickly builds Homer's new park and paints the town in the team colors (orange and purple) and changes all of street names to football related names.
On the day when Springfield is officially announced as the new team, the Commissioner gets confused by all of the new street names and gets lost. He stops for directions at the Simpsons' house and is greeted by Grampa Simpson, who welcomes him in after he states that he needs to make a phone call as well as use the restroom. However, Grampa starts to fear that the commissioner is a burglar after seeing a news report that stated that burglars are often people who do claim to want to use the restroom and make a phone call, with Snake as an example within the interview. Wanting to protect the family valuables, as well as be hailed as a hero to the populace, he attacks him and ties him up. The rest of the family arrives home disappointed that the commissioner didn't show and is shocked to find him tied up in their living room. The commissioner is so angry that he declares that the Meltdowns will never be and leaves, never to return.
The entire town starts to hate Grampa, and the expensive stadium has to be used for farmers' markets. Reverend Lovejoy posted the daily message of "Jesus hates you" in front of the church namely to Grampa, and Grampa was later placed in a burning building by the fire department after saving a little girl. Grampa is now the town pariah. The Jewish Old Man, after expressing his hate of Grampa by spitting on him, suggests that he see a doctor. Grampa says he doesn't need to see yet another doctor since he's already seen several, and even had a medical checkup from the receptionist. The Jewish Old Man then explains that the doctor in question, Dr. Egoyan, helps old people kill themselves. Grampa expresses reluctance at wanting to be "euthanized", as he prefers dying with dignity such as slipping on a shower. The Jewish Old Man asks that he at least visits the doctor first, and mentions that there is a pie store near the clinic. Grampa is so depressed that he decides to seek out Dr. Egoyan who will help him commit suicide. The doctor tells Grampa to reconsider, and Grampa decides that if anyone calls him in the next 24 hours, he won't go through with his plan. The call never comes (Homer did plan to call Grampa when Marge suggested that he shouldn't stay mad forever, but got sidetracked when a call came in just as he was about to make the call and he was asked to participate in a survey about any movies that came out, and apparently forgot for the remainder of the 24 hours) and Grampa goes back to the clinic the next day. Grampa comes very close to being killed but the police show up just in time to stop it, as well as arresting Egoyan, both because he killed Wiggum's brother-in-law (he was the patient who underwent the procedure before Grampa) and because the voters overturned the assisted suicide law.
Grampa thinks he's dead and runs through the town, seeing "Hamburger Heaven" and a Charlie Chaplin impersonator. He soon learns that he isn't dead when stumbling upon the rest of the Simpson family dining at Luigi's restaurant and initially thinks they're dead until Lisa points out that they aren't, and after briefly admitting that he nearly committed suicide when angrily remarking that if he is going to commit suicide, he might as well do the jobe himself, gets a new lease of life and decides to live it up. Meanwhile, the city decides to turn the unused football stadium into an arena for bull fighting upon a Spanish bull fighter entrepreneur's suggestion. Despite Lisa's protests, Grampa decides to become a matador. Grampa wins his first fight with a bull, but he decides that killing bulls isn't his forte and talks to Lisa about giving up. Grampa isn't sure, but in the next fight he sees the bull that he's about to kill and decides to spare its life. He releases all the bulls, which immediately start running through the streets of Springfield, causing a great deal of destruction. Lisa is proud of Grampa and the two reconcile, floating in the air by balloons attached to lawn chairs. However, two bulls start to fly up with balloons on their tails and horns, worrying Grampa and Lisa.