Through the show's history, the tone of the chalkboard gag has veered from pop culture commentary ("I can't see dead people") to sheer absurdity ("The First Amendment does not cover burping").
But this week's episode was different.
Marcia Wallace, who voiced Edna Krabappel's sardonic elementary-school teacher, passed away on Oct. 25 at the age of 70. The show's producers quickly decided to retire the character, and used Sunday's chalkboard "gag" to make it final.
There was no snark, no wackiness; just a sad-looking Bart gazing at one line on the chalkboard: "We'll really miss you Mrs. K."
We really will.