Marge, Bart, Lisa and Maggie go to Principal Skinner to get Maggie enrolled into Springfield Elementary after returning home from Gaia. Principal Skinner accepts her in and to make her feel comfortable, he places her in with Lisa's class. While Principal Skinner takes Bart to his class (since Mrs. Krabappel hates him so much, naturally) Lisa introduces her sister to the rest of the class while Miss Hoover shows not much interest.
Will Maggie be able to adjust to a simpler life in Springfield? Will she be able to fit in at school? and most importantly, will Milhouse confuse her for Lisa?