Bart buys Lisa a Malibu Stacy convertible as a Christmas present. However, the car turns out to be a Transformer. The robot transforms all of the technology in Springfield into robots so they can wage war with each other. Just as two machines prepare to face off, Marge asks why the robots are at war with one another; as it turns out, they cannot even remember. Thanking Marge, the two sides declare that they will work together to conquer the human race, and use the residents of Springfield in a game of foosball.

Homer takes Maggie to a daycare and encourages her to enjoy a mural featuring Krusty the Clown to make her feel better while she is away from her parents. Krusty arrives to have the images of his face sandblasted from the mural, as his likeness is trademarked and used without his permission. An outraged Homer shoves Krusty in retaliation, sending him flying into a wood chipper and shredded alive. Homer is later approached by two advertising agents who have heard of his deed and explain their plan to use celebrities' likenesses in advertising without issues over permission by simply killing the celebrities who refuse to lend their names to advertising. Homer is then hired as a celebrity assassin, taking out such famous faces as George Clooney (by drowning him in cement), Prince (by strangling him with his own guitar), and Neil Armstrong (by causing an Air and Space museum exhibit to crash on top of him). In Heaven, the dead celebrities are outraged by this and stage an attack on the living, with Homer as their main target. Ghost Krusty blasts Homer in the head with a shotgun, killing him. Homer gets revenge by locking out all the celebrities in Heaven, but the joke is on him when an apparently gay Abraham Lincoln pretends to be Homer's friend so he can hit on him for all eternity.

Milhouse waits in a pumpkin patch on Halloween for the Grand Pumpkin (which Bart made up) with Lisa. After Lisa sees everyone at school having a Halloween party, she grows tired of waiting and leaves in frustration. Milhouse starts to cry and his tears and childlike belief bring the Grand Pumpkin to life. However, the Pumpkin is appalled to find that his kindred pumpkins are being carved up on Halloween and made into pumpkin bread, originally thinking it was bread especially made for pumpkins until Milhouse revealed it is made from them, and vows revenge. He devours Homer as he carves a pumpkin, then marches to the school and eats Nelson who threatens to stab a yellow pumpkin. It becomes apparent at this point that the Grand Pumpkin is racist towards this type of pumpkin and then eats Groundskeeper Willie after being offered roasted pumpkin seeds. Realizing that Milhouse can bring things to life by believing in them, Lisa tells him about "Tom Turkey," a symbol of Thanksgiving. Milhouse starts to believe in Tom Turkey, who comes to life and kills the Grand Pumpkin, freeing everyone he ate. However, when Tom Turkey learns that people eat turkeys on Thanksgiving from Bart, he vows revenge and starts angrily chasing children around the school, devouring some of them whole as Marge wishes the viewers happy holidays.