Homer decides to buy Marge a koi pond for their anniversary. Marge is delighted by it, but as her and Lisa sit by the pond and meditate, a high-pitched scream fills the air. The screamer turns out to be a six-inch caterpillar, which is perched on a leaf floating in the pond. A scientist from the Environmental Protection Agency tells Homer that the tiny creature is an endangered species known as the screamapillar, and technically, the Simpsons are responsible for its safety and well-being. The family responds by tending to the bug’s every need…until Homer accidentally crushes it with a book. Horrified, Homer attempts to bury it before anyone is the wiser. But the EPA scientist catches Homer in the act. Luckily, the bug recovers from its injuries, and a judge later sentences Homer to perform two hundred hours of community service. Eventually, Homer ends up bringing food to the elderly as part of the Meals on Wheels program. During one trip, Homer encounters Mrs. Bellamy, an old woman with an axe. Horrified, Homer takes refuge inside a closet, where a skeleton hangs in the darkness. Homer screams.

Homer begs Mrs. Bellamy not to kill him. But Mrs. Bellamy explains that she only uses the axe to cut her food, and the skeleton in the closet is a Halloween costume. Mrs. Bellamy and Homer become friends, and soon after, Bellamy asks Homer for a favor, which turns into another favor, and another. Marge realizes that Bellamy is taking advantage of Homer’s generosity and decides to confront her. But soon after, Marge finds herself performing Bellamy’s bidding. One day, a loud scream is heard in Bellamy’s house…a scream that sounds not unlike one that might be uttered by Carmen Electra. Homer and Marge rush into Bellamy’s study, where Bellamy is lying on the ground. A burglar smiles at Homer and Marge, revealing a mouth full of shiny braces. He jumps out a window. Soon after, Mrs. Bellamy dies…a pair of scissors protruding from her back. Wiggum and his men investigate the incident, and soon after, news reporter Kent Brockman informs viewers that Homer and Marge are the prime suspects. Later, police raid the Simpson home and discover Mrs. Bellamy’s necklace in Maggie’s room. Wiggum places Homer and Marge under arrest and charges them with Bellamy’s murder.

Bart, Lisa and Maggie are placed in the foster care system, and soon find themselves living with Cletus and Brandine. Meanwhile, Homer and Marge stand trial, are found guilty of murder and are sentenced to die in the electric chair. Afterward, Homer confesses to the crime and claims he acted alone. Marge is set free, but Homer’s plan to win his own release by having Marge claim she acted alone fails. Homer is strapped into the electric chair, but as the executioner throws the switch, music plays and a banner reading “You’re on FRAME-UP!” comes descends from above. It turns out that Homer’s been the latest victim of a new FOX reality show. And it also turns out that Bellamy was Carmen Electra in disguise. Marge unties Homer from the electric chair
and remarks that she’s lucky to be married to such a selfless and loving man.