When an insulted Nina has had enough and quits, Harry becomes secretary to Dick and Dr. Albright.

Bud's pen-pal from prison and her boyfriend pay a visit to the Bundy household and takes the family hostage, but Kelly ends up falling in love with the boyfriend.

Kent Brockman does a human interest story about Frank Grimes. Frank Grimes is a man who has had a VERY difficult life and Burns sees the report and tells Smithers to hire him. When Grimes comes to work at the plant, he meets Lenny, Carl, and Homer. All three of them are very stupid in this episode, but no one more so than Homer. Grimes can't stand any of them, especially after Homer starts calling him "Grimey". He is very concerned that Homer is an unsafe employee, after Homer nearly drinks acid and "Grimey" saves his life. Then Burns yells at Grimes about it and Frank Grimes decides to get even. He gets Homer to enter a nuclear plant design contest, but doesn't tell him that it is for kids only. Although he is an idiot, Homer works hard at it and wins the contest. Everyone is impressed with Homer and this sends Frank Grimes over the edge. He has a breakdown and accidentally electrocutes himself. At his funeral, Homer once again steals the show. Meanwhile, Bart makes the winning bid ($1) on an abandoned factory at an auction and hires Milhouse as his night watchman. They do a lot of dangerous things in the building until one day, it tips over and crumbles.

With hours before Kelly's wedding, Al learns that Kelly's new beau is lusting for other women and since Kelly is his daughter, he takes offense to that.

Hank wants to have the best lawn in the neighborhood for Cinco de Mayo, and he decides that Dale's weekly bug-spraying is hurting his lawn. He tells Dale not to spray his lawn anymore. The war begins. Meanwhile, Bobby captures the Queen Fire Ant, and her hold on him becomes hypnotic.

After a man sees a woman trapped inside a bowling alley pin setter, he goes for help and finds police standing next to a body of the same woman. Mulder and Scully join the investigation and follow up this lead which the police won't bother with, and they are led to a mentally challenged man who works at the bowling alley.