Mrs. Krabappel assigns each student in her class a sack of flour to be cared for as if it were a real-life baby. As a child of irresponsibility, Bart scoffs at the task and heads to the Android's Dungeon to grab the newest (and last) copy of Muta-Grunge X, just barely beating Jimbo, Dolph, and Kearney to it.
The next day, annoyed at Milhouse's and Martin's pressuring to stick with the task, Bart leaves his flour-baby on the school playground during recess. That night at dinner, Marge tells Bart that she's proud of him for gaining responsibility in his life, which secretly touches Bart enough to go rescue his flour-baby when Jimbo's gang holds it for the ransom of his comic book. With help from Milhouse, Bart recovers his flour-baby and still gets to keep his comic.
Two weeks later, Bart passes the assignment with flying colors. He has been commended with the "Like Father Like Son" award for his merit in parenting.