Postcards from the Wedge
Postcards From the Wedge is the fourteenth episode of Season 21.
Plot
Homer and Marge receive a letter from Edna Krabappel informing them that Bart is one month behind on his homework, despite Bart's best efforts to stop them from receiving it. Homer is supportive of increasing Bart's workload (so long as he does not have to help Bart with the homework). Marge, however, is concerned that the heavy workload will have a negative effect on Bart's enthusiasm for education in general. When Bart realizes his parent's opposing viewpoints, he uses it to avoid homework entirely. Lisa explains that homework is a wedge issue, an issue that sharply divides two parties who may otherwise agree on most things.
Marge and Homer begin to argue more and more, as Bart manipulates them against each other. Marge seeks council from Ned Flanders, who recalls having a minor argument with Maude on the day she died, saying it has haunted him every day since. Marge consults Selma and Patty, who encourage Marge to stick to her guns, even if the issue would endanger Marge's marriage, prompting Marge to relent and apologize. Meanwhile, Homer falls asleep at work, dreams about accidentally killing Marge, and realizes that he too wants to apologize. The two spot each other in traffic, rush out of their vehicles and embrace. They then decide to let Bart fend for himself.
Meanwhile, Bart and and Milhouse play a prank on Principal Skinner. To evade capture by Skinner, Bart and Milhouse hide in the abandoned Springfield Subway System where they discover the subway trains still work. They race down the tracks and cause a seismic tremor to shake the town. Homer and Marge fail to react to this, having decided not to let Bart get between them. Bart confesses to Nelson that he no longer feels a thrill when he plays a prank. Nelson suggests Bart receives no gratification from pranks unless someone gets angry.
Bart decides to destroy Springfield Elementary, which was damaged by the first subway tremor, by driving the train under it. Homer and Marge find a note from Lisa informing them of this prank and they decide to stop ignoring Bart. They rush to the subway station, where Homer pulls the emergency kill switch. Bart is grounded but is happy that his parents are paying attention to him once more. At the end, Lisa reveals that Bart forged the note about the subway prank, suggesting that he wanted to be caught but promising to keep it secret to protect his bad-boy reputation.
