A hard-working employee, Frank Grimes, is hired at the plant and takes an instant dislike to Homer. Disapproving of Homer's poor job performance and lackadaisal attitude, Grimes eventually declares that he and Homer are enemies. Meanwhile, at City Hall, Bart steps into a tax auction and buys an abandoned factory for a dollar. He hires Milhouse, and the two spend their days wreaking havoc at the factory until it collapses during Milhouses graveyard shift.

Hoping to win Grimes's favor with a nice family dinner, Homer invites him over to discuss an important work issue. However, when Grimes sees Homer's beautiful home and family, he becomes even more bitter. To expose Homer's stupidity, he enters Homer in a children's contest to design a nuclear power plant. Homer wins the childrens' contest and when he is lauded by his peers, Grimes goes berserk. Immitating Homer's behavior, he runs amok throughout the plant and electrocutes himself. As he is laid to rest, the mourners laugh good-naturedly at Homer, who drools and mumbles in his sleep.