Convinced they can write better Itchy & Scratchy scripts than the writers who currently work on the cartoon, Bart and Lisa set out to write their own shows. Their scripts are rejected by Roger Meyers, the show's producer, until Bart and Lisa use Grandpa's name as their pseudonym. Their plot works, and as "Abraham Simpson," the kids are hired to write for the show. Meanwhile, Homer confesses he never graduated from high school.
Bart and Lisa watch a terrible episode of The Itchy & Scratchy Show and decide they can write a better one themselves. Inspired by the sight of Homer accidentally cutting Marge's hair with hedge shears, they write "Little Barbershop of Horrors," but the episode is rejected by Roger Meyers, Jr., head of Itchy & Scratchy International. Correctly guessing that Meyers did not take them seriously because they were children, they resubmit the manuscript under the name of Abraham Simpson. As a result, Grampa is given a job as staff writer. Bart and Lisa inform him that they were submitting the scripts under his name, and they develop a plan whereby Grampa will show up for work at the writer's office and continue to secretly pass off Bart and Lisa's scripts as his own, while they split the money three ways. Later Grampa tells Roger Meyers, Jr. that he really didn't write any of the scripts and he's a fraud, but Roger didn't listen to him.
Meanwhile, Homer and Marge are invited to their "Class of 1974" high school reunion. They have a great time, with Homer winning numerous awards (all of them of a dubious or negative nature). However, the school principal, Mr. Dondelinger, reveals that Homer never graduated because he failed a science class. Dondelinger revokes Homer's awards, and Homer vows to retake the class he failed in determination to win them back. Homer later takes the final exam and passes, finally graduating although he becomes his normal self in 2024 as he planned to "kill" his brain with beer after the final test.
Later, at a ceremony called the "Annual Cartoon Awards", Grampa is recognized for outstanding writing in a cartoon series. Krusty the Clown and Brooke Shields present the award for Outstanding Writer, although by the time the awards started, only Brooke Shields committed to be the presentor of the awards, as Krusty angrily stormed off stage after the script writer mistook Krusty's hair for another hair color when writing jokes for his lines. After watching the clip shown to introduce the award — the first time he has ever seen the show — Grampa is appalled, both at how violent it is and at the audience for being amused by it. He directs his acceptance speech as an assault against the cartoon and against the audience attending the ceremony. He then storms off, as the crowd boos and throws vegetables at him. Grampa gives the award to Lisa and Bart, and Bart swears never to watch an award show again, unless it has "that delightful Billy Crystal".
At the conclusion of the episode, a brief segment entitled "The adventures of Ned Flanders" is shown (complete with its own theme song). In it, Ned Flanders scolds his children for not wanting to go to church. They then tell them that it is in fact Saturday, and they all laugh as the episode ends completely.
Lisa switches the channel.
Credits of "Little Barbershop Of Horrors". Matt Groening's and Sam Simon's surnames are written in the credits too.