S10E1: Lard of the Dance

In the episode "Lard of the Dance," the Simpsons kick off their tenth season with a bang — or rather, with Homer discovering the lucrative world of grease recycling. Homer and Bart embark on a greasy adventure, siphoning off grease from various locations in Springfield to sell for profit. It's all going swimmingly until they target the mother lode: the school cafeteria. Meanwhile, Lisa is dealing with her own drama as a new girl, Alex Whitney, arrives at school and shakes up the social scene. Alex is mature beyond her years, bringing a whirlwind of fashion and sophistication that leaves Lisa feeling out of place. Despite her initial resistance, Lisa tries to fit in by attending a school dance organized by Alex. Back at the school, Homer and Bart's greasy escapade hits a snag when Groundskeeper Willie catches them in the act. A messy showdown ensues, leading to a slip-and-slide brawl in the cafeteria's grease-covered floors. Ultimately, Willie reclaims the grease for himself, leaving Homer and Bart's get-rich-quick scheme in shambles. The episode wraps up with Lisa realizing she doesn't need to change who she is to fit in with Alex and her crowd. She embraces her own uniqueness and shares a dance with Milhouse, while Homer, defeated yet again by his own ambitions, returns home covered in grease but none the richer.