Season 20, Episode 17
Bart and Milhouse pull a prank at Springfield Elementary school, but Milhouse takes the rap so that Bart can escape punishment on the understanding that he visits him every day whilst he is suspended. But Bart then falls in love with a new girl he meets at the Springfield Retirement Castle and soon forgets all about his best friend.
Meanwhile, Lisa is horrified to learn that her beloved town will no longer exist in 50 years time when she consults the internet for a school project and is subsequently drugged up to keep her from being depressed.
Notes & Screenshots: Lord Heath