As opening night for the school play nears, Harry catches Annie kissing Ty, which makes him worry that she and Ty are moving too fast with their growing romance. Silver, stressed out from her job as the stage manager, gets some comfort from Dixon. Meanwhile, Naomi tries make her mother and father get back together, but Tracy's mind to divorce Charlie is made up. On the opening night of the play, the star Adrianna's drug use comes to surface from being under constant pressure from her overbearing mother, Constance, and when Brenda discovers this, she replaces Adrianna with Annie in the lead alongside Ty. But when both Brenda and Kelly confide in Constance about her daughter's drug abuse, Constance (a secret drug abuser-in-denial herself) refuses to believe them. Afterwards, Adrianna successfully gets her revenge when she manipulates and breaks up Ty and Annie's romantic get-together at a celebration party at a local hotel.

After spending several days in the hospital recovering from a near-fatal drug overdose, Adrianna tries to make amends with Naomi. But Naomi refuses to forgive Adrianna for her betrayal. While serving her detention, Naomi meets a trouble-making punk, named Ozzie, who could spell trouble for her. Later, Adrianna makes a connection with Navid, who helps her through her situation as she's accepted into a rehab clinic. Meanwhile, Annie and Ethan finally take their rapidly growing romance to a new level during the school's annual homecoming dance, causing Naomi to feel jealous. Dixon asks Silver to the dance, but she turns him down for she feels, in her liberal and radical mind, that Homcomming is the scene of the morally corrupt. Ryan believes that the new student, Kimberly, is a narc after he sees her purchasing drugs. Also, Debbie confronts Tracy about the time Tracy kissed Harry.

Kelly arrives back in Beverly Hills and reveals to Silver what happened between her and Dylan during her trip. She also confronts Ryan, who has taken a leave of absence, about the rumors that he hooked up with a student, while Ryan refuses to explain his actions to Kelly or anyone else as not to jeopardize Kimberly's undercover status to nail the drug pushers at West Beverly. On Annie's 16th birthday, Naomi sees her kissing Ethan and decides to get back at her by inviting Annie's old boyfriend, Jason, to her birthday party hoping it will break up her and Ethan, who continue to debate over keeping their blossoming romance a secret... unaware that everyone around them already knows. Meanwhile, Adrianna has dinner with Navid and his large Iranian family and she also finds out that Navid is a virgin. At the end, the big twist comes when Harry's 22-year-old illegitimate son, Sean, visits the Wilson family for the first time during Annie's party.

Ryan Matthews returns to his job at West Beverly High which causes a mixed reaction for both Kelly, as well as Silver who finds herself writing a class paper on the book 'Heart of Darkness' to win back his trust after he rejects her from his class. Meanwhile, Annie decides to audition for the school's drama production of 'Antony and Cleopatra' and sets her sights on the lead, while she asks Ethan to audition for a role in the play so they can be closer together, while Annie also has a run-in with her one-time boyfriend Ty Collins. Adrianna becomes more uncertain about her pregnancy and refuses to deal with the problem. When her mother goes missing, Naomi is asked by her father, Charles, to move in with him and his mistress at their Malibu beach house which makes the situation very awkward and uncomfortable for everyone. Elsewhere, Silver and Dixon continue to experience bumps in their relationship which leads him to decide if he wants to end his romance with her.

As Valentine's Day approaches, Adrianna's pregnancy now becomes the talk of the entire school as her 'baby bump' begins to show, while Navid continues to ignore her and grows more closer to Nika. Meanwhile, Silver asks Naomi for help in planning to make the best Valentine's Day ever for Dixon by setting up a dinner at the hotel where Naomi is now living at. But later, Dixon freaks out when Silver gets a much too permanent tattoo of their love to try to bring them back together. Also, Ethan's friendship with Rhonda continues to blossom which makes Annie very jealous, while she begins taking acting workshop lessons and tries to find her own motivation. But Rhonda begins using her medical condition to manipulate Ryan's too-trusting kindness to lead him more closer to her. Elsewhere, Naomi meets Liam Court, a bartender at the hotel in which they click romantically at once, but suspicion plagues Naomi as to whom Liam is when he does not want to talk about his personal life.

As West Beverly prepares itself for the annual prom, Annie, Adrianna, Naomi, and Silver go out shopping together for the right evening gown to wear and try to get all glamored up for the event by visiting a famous hair stylist. A dateless Annie agrees to attend the event with the socially awkward Charlie, who has a massive crush on her. However, when he realizes that Annie is only interested in being friends, Charlie turns against Annie... showing his true repressed psychopath colors to plot a cruel revenge. Naomi attends the prom with Liam while she learns that Jen has emptied out her trust fund to support them living at Jen's new house. Meanwhile, Dixon is nominated for prom king, while Ethan learns that he has been accepted into lacrosse camp for the summer. Also, both Kelly and Harry take action to help Liam get on the right track, while he continues to try to temp Annie to embrace her own dark side as he has with his own. Ryan grows more closer towards Jen, and he also ignores Kelly's warnings that Jen is a devious, sociopath seductress whom is using him for self interest. At the prom, Harry informs the students in attendance that any after-prom activities will be dealt with punishment, while Navid provokes a fistfight with Ty when he reacts with indifference over the pregnant Adrianna's unborn child which is in fact his. When Silver learns that Dixon has nominated himself for prom king, she decides to enter for prom queen as a write-in candidate and finally gets to speak her mind to the attendees.