Blackboard joke: I will not do anything bad every again.
Couch gag: The family sits down on the couch, but one by one, everyone is squeezed off the couch by Homer.
In the dining room, a dressed up and anxious Marge sets up snacks and appetizers for a cocktail party. When the doorbell rings, Marge and Homer send the kids to bed and greet their guests at the door. Ned and Maude Flanders are the first to arrive and Ned requests to be the bartender; he shows off his mixing skills and makes Homer a drink. A less than impressed Homer is surprised to see that he actually likes Neds drink and after quickly downing one, he orders another. Marge walks by and reminds Homer to go easy on the alcohol.
Later on, the party is well under way, and a drunken Barney tries to ask out Marges sister Patty, who sprays him in the face with some mace. On the other side of the living room, a tipsy Homer slips a novelty ice cube with a fly trapped inside, into Dr. Hibberts drink, however, Dr. Hibbert is not amused. As the evening goes on, Homers antics continue as he becomes progressively sloppier and drunk: He stumbles around the living room with a lampshade on his head in an attempt to entertain the crowd; he tells off a man whom he doesnt even know; and Marge catches him staring at Maude Flanders cleavage, after he persuades Maude to bend over and dish out some peanuts for him.
At the end of the night, as the guests file out, Marge wishes them well and apologizes for Homers behavior. Homer has now passed out on the floor in the foyer, and as Dr. Hibbert leaves, he recommends to Marge that she roll him onto his stomach if she wants him to live through the night. After everyone is gone, a humiliated and embarrassed Marge tries to wake up Homer and tell him how she feels. But she becomes even more upset when Homer is unresponsive. She leaves Homer to sleep it off on the floor for the night.
The next morning Marge, wakes up Homer, who is still sleeping on the floor, by vacuuming all around him and intentionally bumping him in the head with the vacuum. Marge leads Homer out to the car, so they can fight privately, away from the kids. She asks him if he remembers how he acted the night before, and Homer flashes back to the ill-fated evening in his head. His recollection of events involves him sitting at a table with sophisticated and urbane people, as he entertains them with witty banter. Marge flashes him back to reality and reminds him that he made a complete fool of himself and embarrassed her in front of their friends. Marge informs Homer that she is going to go to church alone, while he must stay home and explain his actions from the previous night to Bart. Up in Barts room, Homer admits to Bart that he did not know when to say when, and apologizes for his actions.
At church, Marge sits in a pew alone, and a remorseful Homer stumbles and finds a seat near her, as if to seek forgiveness. During the service, Reverend Lovejoy announces a retreat that he will lead, for married couples at a lodge on Catfish Lake. After the service as Homer talks with Reverend Lovejoy about not needing to go on a retreat for his marriage, Marge signs up for the retreat behind his back. When Homer turns and sees what Marge is doing, he unsuccessfully tries to stop her.
At home, Marge and Homer pack for the marriage retreat and Homer grabs his fishing gear, but Marge angrily tells him that there will be no fishing on this trip. Downstairs, Marge answers the door for the babysitter, but when the babysitter gets a glimpse of Bart, she flashes back to a previous babysitting encounter with him. In the flashback, a baby version of Bart steals the car keys and chases the babysitter in the family car. The flashback sends the babysitter into a screaming fit and she runs away. Marge is now faced with finding a babysitter for the kids on short notice. Homer doesnt seem deterred though, as he proclaims that if they cant find a sitter, they just wont go on the marriage retreat. Bart offers his services, but, Marge settles on using Grampa, who happens to be sleeping on the family room couch.
Outside, Marge gives Grampa some last minute instructions and notes, while Homer sneaks his fishing gear into the trunk of the car. Marge and Homer say their goodbyes and speed away for a weekend at Catfish Lake for the marriage retreat. As soon as Homer and Marge are out of sight, Bart produces another note and hands it to Grampa, telling him that his parents forgot to give it to him and that the note contains a list of things that he and Lisa can and cant do.
Homer and Marge travel on a road surrounded by mountains on the way to Catfish Lake, and Homer sees a road sign for a general store and gas station that sells fishing bait. A little further down the road Homer stops for gas, even though the tank is full. Once inside the store, he secretly purchases some worms. The elderly store clerk inquires about Homers trip and Homer tells the man that he is going to Catfish Lake for the weekend. Upon hearing this, the clerk informs Homer of the legendary General Sherman, a 500 pound catfish that has never been caught. A determined Homer grabs his worms and walks out of the store, declaring that he is going to catch General Sherman. Homers proclamation leaves the clerk and the locals hanging out inside stunned.
Back in Springfield, Bart is busy taking advantage of Grampa who is now driving the kids around town, to the places they want to go. Meanwhile, Marge and Homer arrive at the lodge and are greeted by Reverend Lovejoy and his wife Helen. Inside the lodge the other two couples, John and Gloria, and Maude and Ned Flanders, have already arrived, and everyone goes around the room introducing themselves. Reverend Lovejoy starts with the angry John and Gloria first; he asks them explain each others faults and after they do so he asks them to gaze into each others eyes. When they do, they both instantly fall back in love with each other and John carries Gloria away in his arms, as they both feel cured. Ned and Maude go next and Ned explains to the group that it bothers him when Maude highlights passages in his Bible when she can't find hers. Homer interrupts Ned with a sarcastic comment and Reverend Lovejoy asks Homer to go ahead and share with the group the things about Marge that bother him. Homer admits that Marge is perfect, except when she nags at him. Then Marge is asked to explain the things about Homer that bother her. She starts rattling off a list of things off the top of her head, as Homer slumps in his seat in shame.
Back in Springfield, Grampa takes the kids shopping, while Lisa reads off of a fake shopping list that contains nothing but ice cream and Bart smokes a cigar. Meanwhile, it is now late into the evening at the lodge, and Marges voice is hoarse, as she continues with her list of bothersome things about Homer. When she finally finishes, Reverend Lovejoy calls it a night and sends everyone to their respective cabins. Back in Springfield, Bart and Lisa watch the violent and bloody McBain movie and send a feeble Grampa to bed.
The next morning, Homer gets up very early and tries to sneak out, to go catch General Sherman. Just as he is about to make it out the door, Marge sees him and confronts him. Homer repents and asks her to help him and she tells him to get back into bed. Homer does, but when he cant sleep, he asks her if it is okay to go for a walk and Marge says yes. Outside, Homer walks along the edge of the lake deep in thought, trying figure out how to be a better husband. A young fisherman steps away from a dock and leaves his fishing pole; Homer sees the pole and grabs it, while trying to tell the young fisherman about the forgotten pole. But before he can get any words out, a large fish grabs the fishing line in the water and yanks a screaming Homer down the length of the dock, into a row boat, and out into the lake.
Homer fights the fishing pole and is towed around the lake by the elusive General Sherman. When Marge wakes up, she looks out the window and is disappointed to see Homer fighting with the fish in the lake. Back in Springfield, Bart and Lisa force Grampa to make them coffee for breakfast. Later at the house, Bart dials up Milhouse on the phone and tells him to spread the word about a party at the Simpson home that afternoon. A montage shows Milhouse, Otto, and Snake calling around and spreading the word about his party. Back at the Catfish Lake, Homer is struggling with General Sherman on the lake, while at the lodge the couples perform a trust exercise. Reverend Lovejoy consoles and sides with Marge, telling her that her rusty marriage is not her fault. Their failing marriage is really Homer's fault because he cares more about fishing.
In Springfield, Grampa is busy taking a shower and when he steps out of the bathroom in his towel, he is shocked to see the house a complete mess and filled with kids running all around. At Catfish Lake, a weary and tired Homer continues to grapple with General Sherman. Back at the house, Bart plays host at his party, as his guests run around trashing the house. Grampa makes his way downstairs and tours the damage, and tries to make the partying kids to listen, but to no avail. Back at the lake, after fighting General Sherman for hours, Homer hits the fish over the head with an oar and drags him in the boat.
At the house, the party is over and Bart thanks his guests for coming, while Grampa sits on the couch with his face in his hands, sobbing about being a failure as a babysitter. Bart and Lisa feel remorseful and decide to grab some rags and a mop and commence to cleaning up the messy house. As the kids walk away to grab some cleaning supplies, Grampa looks up and his crying changes into an evil laugh. At Catfish Lake, a victorious Homer celebrates as he rows himself and General Sherman back to the dock, where an angry Marge awaits, tapping her foot. Homer tries to explain the importance of General Sherman, but Marge wont hear any of it, and in a fit of rage, Homer proves that he loves Marge by pushing General Sherman back into the water. A stunned Marge realizes what Homer has done for her and she jumps down into his arms for an embrace. As the two hug, General Sherman jumps up out of the water and gives a wink towards the camera.
Back at home Bart and Lisa furiously clean the house and finish just in time, as Marge and Homer arrive back home. Grampa and the kids greet Marge and Homer at the door and an impressed Marge asks Grampa how he managed to keep the house spotless. Grampa reveals to Bart and Lisa that he faked the crying to make them feel guilty, and a shocked Bart and Lisa watch, with their mouths agape, while Grampa walks away laughing.
Back at the roadside store, a man buys some fish bait, and the elderly store clerk tells the new legend of General Sherman. The legend includes a 7 foot tall man, with a shock of red hair, named Homer, who was the only man to come close to catching the elusive fish.
End Credits: The normal Simpsons theme plays as the credits roll over a black background.