In a parody of "24," the school's Counter Truancy Unit tries to stop three sixth-graders planning to disrupt the school bake sale with a stink bomb.

With Lisa's encouragement, Marge pursues her dream of becoming a ballerina. But when Marge auditions at the ballet academy, Lisa is invited to enroll. Unfortunately, Lisa becomes addicted to secondhand smoke from the other dancers. Meanwhile, Homer's beef-jerky operation runs into a snag.

Homer and Marge remember the ups and downs of their marriage through a series of flashbacks, including the time they each began flirting with guests at a glamorous party - a situation that led to a food fight and an unexpected swim in the pool.

Lisa infiltrates a convent in order to steal back Maggie who was accidentally taken in by nuns. While in the convent, Lisa uncovers a series of cryptic clues leading to a hidden jewel in Springfield. With help from resident history buffs Principal Skinner and Comic Book Guy, Lisa sets off to find the coveted prize. But Springfield's Freemasons are also hot on the trail of the jewel, and Lisa must race against them to find the jewel and rescue Maggie.

When Miss Hoover asks her students to research their family history, Lisa is horrified to discover that most of her ancestors were bad people – a motley crew of horse thieves and deadbeats. But while rummaging through the attic, Lisa happens upon a diary kept by her ancestor, Eliza Simpson. As Eliza’s story unfolds, Lisa learns that her family was part of the Underground Railroad, a group that helped slaves escape to freedom. Eliza recounts liberating a slave named Virgil, but when Lisa presents her findings at school, some of her classmates refute it, leaving Lisa determined to exonerate her family’s name.

Lisa's school project leads to the discovery of a new drug that makes the elderly less cranky and more tolerable.

Karma gets the best of Homer after he gets his friends in trouble, and as a result, his bedwetting problem worsens. The family goes on a mission to infiltrate his dreams to search for clues in his subconscious to determine the source of his problem. But just as things take a dangerous turn in the dream, a figure from Homer's past appears, and he is finally reassured that the fond memories of his mother Mona (guest voice Glenn Close) remain alive, giving him just the right amount of reassurance to cure him of his problem.

Springfield's Easter is ruined by a prank and all fingers point to Bart. It is up to Lisa to save her brother, in a student court presided over by Attorney General Janet Reno. Meanwhile, inspired by an old comic book, Mr. Burns becomes an ineffectual superhero—fruit bat man.

Bart feels guilty after he wins the annual "last day of school" race around Springfield Elementary School, with help from Nelson, who beats up the frontrunner, Milhouse. Meanwhile, Homer tries to bring back 4th of July fireworks after they are canceled due to budget cuts.