Bernadette gets irritated at Penny when she doesn't study for her pharmaceutical job before she starts training. Penny makes plans with Amy and doesn't invite Bernadette. They gossip about Bernadette in the "spirit of science."

Bernadette invites Amy out for a drink, but doesn't want Penny to come out. She's frustrated that Penny's not taking the job seriously and is getting manicures instead. Amy feeds Bernadette's frustration. She's playing both of them against the other and enjoying every minute of it.

Sheldon visits HR regarding the university's decision that he has to stick with String Theory. During his time away, the university came up with a solution. They offer him a promotion to Junior Professor, which means he'd have to teach a class, but can do any research. Sheldon's upset with the offer. He doesn't want to be a teacher and relates it to being a babysitter.

After not wanting to teach the class, Sheldon is upset when no one signs up because he has a reputation. Howard offers to sign up for his class and then Sheldon ridicules him and claims he's not smart enough. Sheldon quizzes Howard, who answers correctly. Howard claims engineers are as smart and Sheldon freaks out.

Sheldon works on a lesson plan to try and confuse Howard, but his plan backfires. Howard finds out what Sheldon was planning from Leonard and attempts to come to an agreement that Sheldon will teach him rather than try to humiliate him. When Sheldon doesn't agree, Howard decides to be a bad student for his bad professor. He listens to music, then shoots a spit ball into Sheldon's mouth.

Amy's bad mouthing both friends makes her feel cool. Penny decides to stay home and study, so Amy calls Bernadette, but she's going to help Penny study. Badmouthing over. Bernadette tells Penny she's ready and they call Amy to go out.