The Simpsons attend a soccer match between Mexico and Portugal. When the game starts, the crowd begins to lose interest and, under Groundskeeper Willie's direction, it turns into a violent football riot. The riot spreads throughout the town. Afterwards, Marge fears for the family and tells Homer to pay for a Home Security System. Finding out that the system will cost $500, Homer decides to save money by buying a firearm instead. After the five-day waiting period, Homer surprises Marge with his new revolver from a local gun store, Bedlam Bloodbath & Beyond (a play on the store named Bed Bath & Beyond). Marge is horrified and demands that he get rid of the gun at once. Homer persuades Marge to come with him to the local National Rifle Association meeting to try to get her to change her mind, but after the meeting, she still remains unconvinced.
Homer starts to treat the gun as though it were a toy, casually carrying it into the Kwik-E-Mart and frightening Apu into thinking he will rob the store, firing bullets to retrieve items from the roof and shooting dinner plates as if they were clay pigeons with Bart. Finally, after a near-fatal accident at the dinner table, Marge reveals just how uncomfortable with the gun she is, and begs Homer to get rid of it. Homer promises to do so, but hides it, loaded, in the vegetable crisper instead. Later, Bart and Milhouse discover the loaded firearm and play with it in the kitchen. Marge steps into the kitchen just in time to stop them, and berates Homer for breaking his promise, by giving Homer an ultimatum.
After this, she promptly leaves with some suitcases and the children in tow and checks into "Sleep-Eazy Motel" on Selma's recommendation. That night, Homer hosts an NRA meeting at his house but the other members are far from impressed by his reckless gun usage and he is kicked out of the association, therefore and his own house. Realizing what his behavior has cost him, Homer goes to the motel where Marge and the children are spending the night, meaning to reconcile.
Homer and Marge make up, after Homer explains he has finally gotten rid of the gun. While leaving, Snake arrives to rob the desk clerk, demanding the cash register's contents while holding a knife to Mayor Quimby's throat. Homer pulls out his gun, foils the robbery and stops Snake from decapitating Quimby. Marge is angry with Homer for lying again, but while he tries to apologize, Snake snatches the gun, even though Homer reveals the gun is not loaded, but Snake tricks Homer into handing over the bullets anyway. Some of the other NRA members arrive and stop Snake from shooting the Simpsons, but he runs off with the money all the same. Homer finally says he does not trust himself and asks Marge to throw the gun away herself, because he feels sure that his attachment to it will just make him lie to her repeatedly. However, just as Marge is about to throw away the gun, she sees a reflection of herself holding it in the bin lid and likes what she sees in her reflection and decides to keep it.