[3] In this episode, Lisa is angry that Miss Hoover gave everyone the same grade on a project, so she follows her home to learn about her point of view.
When Hoover (who is stuck on the floor due to her combination of back pain and laziness) uses an automatic-messaging app to give everyone in the class (even Ralph) the same B− grade, Lisa calls her a hack and refuses to apologize.
She is sent to detention, where the bullies are mean to her until Bart shoos them off with a stink bomb and suggests that Lisa tell Hoover she is "soggy" instead of "sorry".
After riding on a multitude of run-down and dirty vehicles to follow her, and even riding down a hill on a cardboard box (something Hoover does to not hurt her back), Lisa sees what Hoover's lonely life is like and takes pity on her.
He found that the apology works because they pulled off the suspense, and he enjoyed the twist of the bribery.