Adrianna and Navid are forced to make an impromptu exit from the prom when Adrianna goes into labor. Dixon confronts Ethan about Silver when he notices that Ethan might be developing feelings for his girlfriend. Meanwhile, Annie reaches the breaking point when Naomi accuses her of trying to hook up with Liam, and some of her peers (still angry about the after party fiasco) decide to take both verbal and physical action against her.
With prom night quickly approaching, Annie, Adrianna, Naomi, and Silver get glammed up by a famous stylist. A dateless Annie agrees to attend the event with the extremely nerdy Charlie, who is massively crushing on the popular girl. But when he realizes that her interest is purely platonic, a furious Charlie plots an evil revenge. Meanwhile, Dixon is nominated for Prom King, Ethan gets accepted into lacrosse camp, and Kelly and Harry work to get Liam on the right track.
Following their engagement, Navid and Adrianna celebrate their respective bachelor and bachelorette parties. While Adrianna feasts with friends and family at the Wilson home, Navid and the boys spend a wild night with college girls at a burlesque club. Meanwhile, sparks fly between Ryan and Jen, and Dixon continues to feel unappreciated by Silver.
Now that they have finally sold their home in Kansas, Harry and Debbie have a yard sale, Beverly Hills-style. Meanwhile, Donna talks to Kelly about her separation, and later search for a place for Donna to open a clothing store; Dixon helps Silver in her recovery; Liam and Ethan's unlikely friendship continues; and when a scandal involving Naomi's father comes to light, her trust in Annie begins to falter.
Liam displays his dark side to Naomi, who is stunned but captivated by the intense, handsome bad-boy. Meanwhile, Annie and Ethan face another bump in their relationship when Adrianna makes it known that Ethan and Rhonda shared a kiss, and Silver and Dixon make a video that stirs quite a controversy at West Beverly Hills High.
After recuperating from her health scare, Adrianna returns and tries to make amends with Naomi, but her ex-BFF refuses to forgive her for the betrayal. Adrianna makes a surprising connection with Navid, who helps her through her situation. Meanwhile, Annie and Ethan finally take their rapidly growing romance to a new level during the school's homecoming dance, causing Naomi to feel jealous.
Annie and Ethan get paired up for a class project where they must take care of a baby. This time together forces them to see each other in a new light. At Silver's half-birthday party, Silver and Dixon continue to get closer. Meanwhile, Harry and Debbie must deal with Harry's past when Tracy tells Harry that she's hired an investigator to find their son. Elsewhere, Ryan tries to cope with Kelly leaving and decides to try online dating.
As the opening night of the school play "Spring Awakening" approaches, Ty reveals to Annie his plans for a one-on-one after-party in his hotel room with her. Others at school are concerned about how fast Annie and Ty's relationship is developing. Meanwhile, Naomi won't accept her parents' divorce and Adrianna is confronted about a substance abuse problem, which gives Annie a chance to be the lead in the play.
Annie, Harry, and Debbie are surprised to find out that West Beverly's theater director can't direct the school musical anymore. Kelly persuades Brenda to take over as the play's director, but they end up arguing over Kelly's involvement with Ryan. Meanwhile, Dixon tries to get a part-time job at the Peach Pit and Naomi confronts her father's mistress.
Harry and Debbie plan a family bowling night, but find their plans interrupted by the unexpected arrival of Annie and Dixon's friends. Meanwhile, Annie finds herself torn between Ethan and Ty, Naomi experiences a difficult evening with her father, and Kelly and Silver learn that Jackie's drinking is beginning to spiral out of control.