Lizzie and Miranda are ecstatic about being invited to a pool party given by their heartthrob, Danny Kessler. Mrs. McGuire is excited for Lizzie too until she finds out it's on the same day as grandma's 80th birthday party. She tells Lizzie she has to go to her grandma's instead and Lizzie is furious. The next day at school Miranda temporarily gets on the good side of Kate, the girls' former best friend who has literally and figuratively outgrown them. Kate invites Miranda to hang out with her crowd, causing a conflict between Miranda and Lizzie. At home Lizzie catches her mom on the phone making up a lie to get out of a commitment and accuses her of being a hypocrite. Gordo helps Lizzie to smooth over her differences with Miranda. Mom tells Lizzie she can go to the party after all, but she decides not to and spends the day with Gordo.

Lizzie is dissatisfied with being an ordinary ""B"" student and is looking for something at which she can excel. Surprisingly, she finds out in gym class that she has a real talent for rhythmic gymnastics. But she thinks the sport is stupid and is ambivalent about competing. She trains hard and goes to the regional competition, where a jealous Kate tries to sabotage her performance. Miranda and Gordo help foil Kate's plan and Lizzie wins first place. Her parents are proud but Lizzie decides to give up the sport and go back to being her ""ordinary"" self.

Lizzie's fantasy almost comes true when she is paired up with Ethan Craft in a CPR class at school, but he's so dense that the teacher chooses Tudgeman instead to give Lizzie mouth-to-mouth! Lizzie, Gordo and Miranda realize they are about the only three in school who haven't seen the latest blockbuster movie Vesuvius: The Eruption, which is rated R, and they're determined to get in to see it. When their parents all say ""no"" to their arguments, Gordo decides they should say they are going to play miniature golf, then go see the film. Lizzie is very nervous about lying to her parents, but she pulls it off with ease.

The trio can't get past the ticket-taker, though, and can't slip in the back, so they mingle with the crowd as it is departing a showing and sneak in that way. While at the concession stand, they notice a man choking.

Lizzie finds out in square-dancing class that a guy has a crush on her--but it's Larry Tudgeman! She asks her mom's advice about how to get rid of him, but Mom suggests she find out what he's all about first, intimating that her dad was kind of a geek when she first met him. This isn't what Lizzie wants to hear, but she doesn't want to be mean and consents to go out with Larry. To her surprise, he shows up for the date looking very nice, and--bigger surprise--she actually has fun on their trip to the science museum.

Lizzie is invited to play touch football with the guys, but she is worried when Ethan calls her a "dude," and she feels that she is losing her femininity by playing football.