In the episode, Lisa discovers that Sideshow Bob has become the chief scientist of a massive chemical engineering company, but the two of them bond over their appreciation for high culture.
As Ms. Hoover's class watches a film that Lisa feels does not fit in the lesson plan, they are interrupted by students stampeding in the hallways because it is Taco Tuesday.
After reading about the side effects of eating genetically modified foods, Lisa presents her argument at the parent-teacher meeting at school.
After watching a confusing video, Lisa runs off to do more research and discovers genetically modified foods can actually be a good thing, much to the surprise of her audience.
The mere image of Homer and Marge touching each other gives the teenagers enough reason to pledge to wait until marriage for sex, though this results in them starting a riot in pent-up sexual frustration.
When Lisa quotes Walt Whitman, Bob realizes he has become a monster and attempts suicide by drowning, but then remembers he gave himself gills.
[1][2] Executive producer Al Jean stated that there were only two lines recorded by Wallace remaining, and there was not enough material for a farewell episode.
They summed up, "But the greatest reward of any Sideshow Bob episode is Kelsey Grammer who, some 24 years after his first appearance as the fright-wigged, intermittently homicidal, incongruously cultured Robert Underdunk [sic] Terwilliger, can make the character as vitally funny and menacing as ever.
Praise was given, however, to the episode's B-story involving Marge trying to talk to the local teens about celibacy as "her uncomfortable speaking and inadvertently titillating finger puppets made for some great comic moments."
[6] After the episode aired, Monsanto released a statement saying, "We are glad Lisa did her homework and came to her own conclusions about the facts and benefits of GMOs.