Pete and Debbie are both about to turn 40, their kids hate each other, both of their businesses are failing, they're on the verge of losing their house, and their relationship is threatening to fall apart.

While performing in Springfield, the band Green Day perishes when the lake's pollution dissolves their barge, following an audience revolt after frontman Billie Joe Armstrong proposes an environmental discussion. At their memorial, Grampa Simpson foresees the destruction of the town, but only Marge takes this seriously. Later that day, Homer dares Bart to skateboard naked to Krusty Burger and Bart ends up arrested. Bart considers their neighbor Ned Flanders a better father after Homer refuses to take responsibility for the incident. Meanwhile, Lisa and her new friend convince the entire town to clean their lake.