In the series pilot, social opposites Sam and Brooke are paired as lab partners, to the delight of Carmen, who sees it as a chance for Sam to help her get on the cheerleading squad. Meanwhile, Brooke and Nicole plan the first party of the school year and star quarterback Josh tries out for the school play.

Carmen ditches school the day after the cheerleading roster is posted, and Lily refuses to dissect a frog in science class. Meanwhile, Josh's father embarrasses him at rehearsal; and Mary Cherry stalks Nicole.

Sam writes an exposé about the cheerleaders' school budget, leading to the squad's termination and its remaining funds being redistributed to the drama department. The exposé also heightens the tension between Brooke and Sam as they prepare for their first dinner together with their parents. Meanwhile, Josh must decide between starring in the school musical or playing in the homecoming game.

Brooke, Poppy, Mary Cherry and Carmen are nominated for the Junior Court Homecoming Queen and Nicole pressures two of Brooke's opponents to halt their campaigns. Meanwhile, Sam and Jane move into the McQueens' house, causing an instant turf war between Brooke and Sam.

Sam and Brooke wager on whether or not Sam can land a boyfriend by the end of the week and whether Brooke can prove that her relationship with Josh is more than just physical, with the loser publicly joining an embarrassing club. Meanwhile, Lily hands out condoms to her classmates in response to the popularity of a new singer whose sexual image is mimicked by some students at Kennedy High.

Brooke and Sam are forced to hold their annual Christmas parties together, and Carmen is injured just weeks before the next round of cheerleader tryouts. Meanwhile, Nicole's brooding over the yuletide season leads to visits from the ghosts of Christmas past, present and future.

Mounting tensions between Sam's friends and Brooke's clique lead to a proposed rumble, but the guys intervene and lock the ladies in a school bathroom in an attempt to make them reconcile. Meanwhile, Josh, Harrison and Sugar Daddy get an education on ovulation from a nature film provided by Bobbi Glass.

When Sam, Lily and Carmen dye their hair blonde to prove that the popular girls' power is based on their hair color, Brooke and her friends set out to prove them wrong by darkening their own tresses. Meanwhile, a beautiful, new exchange student is attracted to Sugar Daddy.

Brooke and Sam try to derail their parents' wedding plans by planting false evidence of Mike's infidelity, which leads to a startling announcement from Mike and Jane. Meanwhile, Mary Cherry discovers that her mother is engaged to actor Erik Estrada.

Bobbi Glass ruins the annual "skip day" ritual for the popular and alternative kids by faxing their photos to their favorite hangouts so they'll be caught cutting classes. The kids plot their revenge during an extended musical number. Meanwhile, Sam and Brooke agree to work together to make their parents' rehearsal dinner a success.

Brooke bonds with her long-lost mother--much to her dad's chagrin. Meanwhile, Lily and Sugar Daddy try to save a tree from being cut down, and Carmen delays telling her friends about her pregnancy.

Nicole is desperate to save her popularity, which is falling since she was banned from the Glamazons. She tells Brooke that she should dump Josh and start dating George. Harrison is feeling a little bit jealous about Sam and George flirting, and so he and Nicole team up to make a study on attraction for chemistry class. Brooke and Josh break up. Sam feels like she lost again to Brooke when she sees she and George together. But George tells Sam he is really into her and they kiss. Josh and Lily find themselves attracted to each other when he helps her to send a gay chimp back to his lover in Uganda. Harrison learns more about Mary Cherry and starts to have feelings for her (could it be love?). Jane tells Mike she's pregnant.

Brooke decides to run for student council president, dropping out of the Homecoming Queen election. She asks Harrison to be her campaign manager. They disagree on mandatory drug testing for students and he quits to run against her. Sam, Carmen, Nic and Mary Cherry get nominated to Homecoming Queen. Sam is motivated by George to run for it, but gets too into the spirit. Carmen is sleeping at the school since she is homeless, and Bobbi Glass invites her to her home. Seeing in Carmen herself in high school, Ms. Glass helps her with the contest (even threatening to give everybody an F if they don't vote for Carmen). Nic and Mary Cherry look for help with Hellacious Arke, a past 3 time Homecoming Queen, who is also Ms. Glass's own ""Nicole"" back in her high school days. Brooke misses Josh and sees him and Lily trying cough syrup while spying on them. Motivated by the recent death of a student of cough syrup overdose, she decides to run her campaign on anti-drug platform. Scared to be caught

Clarence dies peacefully while talking to Harrison. His death has a deep impact in Harrison's own view of life, and he decides is not worth to keep the treatment for his cancer. He goes to extreme measures and decides to put an end in his agony, attempting suicide. But Clarence comes back as an angel to give Harrison a view of what the world would be if he had never been born. We see that April would have become a rich successful owner of a fish market (Tunaville); Brooke would have died from anorexia, Lily would have married Josh after pregnancy and they would have become the first family, and among other twisted things, Nicole and Mary Cherry trying to make a living as whores with Sugar Daddy as their pimp.

Lily, Carmen, Mary Cherry and Brooke are peacefully riding Lily's car when they pass by a car crash and notice the Gremlin's license plate, TUNA69, and realize that the car belongs to their classmate April Tuna. The entire school is touched by her death and they make a memorial service in her honor. Everyone's feeling guilty about how they treated her. Josh gets a new hairstyle and joins the ""mullets"" club. Nicole finds out that the cafeteria lady is in fact her long lost birth mom. Sam gets an email from Harrison telling her he loves her and asks her to choose between him and George. Nicole gets an email too, saying what a bitch she is. She admits being a bitch at the memorial service, and April suddenly appears, saying she was not in the car that got crashed.

Ms. Glass wants all the students to write down where did they go for Spring Break and how many they slept with, so, in her own words, she can judge them. Most of the gang say they went to Cancun, and Harrison writes that he went to Yemen as his nose starts to bleed. Ms. Glass deduces he has been infected with the Rift Valley fever that is contaminating everyone in Yemen. Just as Sam was trying to talk to him by his locker, they are both isolated from the rest of the people and the school is shut down in quarantine. During Chemistry, Mary Cherry receives a call in her cell phone from someone who knows what she really did for Spring Break - a low-budget soft porn scary movie - and she has to run for her life as she is chased to be killed. Meanwhile, Lily tells April what they really did for SB. They intended to go to Cancun, but they all stayed in LA and had SB in different ways. Nicole is elected to attract the killer, but since she's not a virgin, and only virgins get chased by killers

Sam and Brooke help deliver Jane's baby (in one of tv's fastest labors) and realize that they can't fight over Harrison, so they both agree on going with him to the prom (ménage?). Nicole is thirsty for revenge and gets George into asking her to the prom, since he is hurt by what Sam's doing. Josh and Lily are trying to handle their marriage, and decide they should get a place of their own, since Lily's mother disapproval has become unbearable. So they move to the now available Ms. Glass's basement. But they have too much pressure on their hands, since Ms. Glass is using them for house chores and they are totally broke, to the point of Lily having to sell organic soap at the school and Josh getting a job as a window salesman. And they're still trying to consume their wedding. Mary Cherry is touched by the sisterhood of Brooke and Sam, and decides she wants a sister too. She asks Nicole to be her sister, but the Devil turns down the offer. Suddenly, Mary Cherry's long lost twin sister (