With Miss Hoover out sick, a substitute teacher takes the class and becomes an inspiring role model for Lisa.

When Marge learns Springfield Elementary is the worst school in the state, she and Homer rent an apartment in the upscale Waverly Hills school district so Bart and Lisa can attend a better school. Meanwhile, Homer moves into the rented Waverly Hills apartment and gets used to the bachelor lifestyle.

Krusty grudgingly adds a pretty, singing cohost named Princess Penelope to his show in order to attract more female viewers. Girls love her, and ratings improve, but Bart and Milhouse want to get the show back to the way it was. The situation gets more complicated when Krusty and Penelope fall in love and decide to get married. Meanwhile, Homer, Lenny, and Carl consider working at a competing nuclear plant when Mr. Burns cuts off their daily doughnut service.