In a memorable send-off, our favorite group from Beverly Hills will come together again after a traumatic event that makes them realize the importance of their relationships.
Jordan calls in a favor from his mother to help out Mark, but in exchange must end things with Naomi. Annie must deal with the betrayal Liam feels from being in her book and Michaela catches Navid and Adrianna during an intimate moment.
Liam and Navid, in an effort to get teenage pro-surfer Cassie to be their first sponsored athlete, ask her favorite musician Olly Murs to do a special performance. Naomi travels to New York to make a good impression on Jordan’s mother, Cheryl with disastrous consequences. Annie decides to publicly say her novel is fiction but Dixon persuades her to tell the truth.
Jordan asks Naomi to plan a launch party for the latest hot writer, known as Author X, which forces Annie to admit that she is Author X. Silver worries that Adrianna is not okay that she is dating Mark. Meanwhile, Dixon finds out that Michaela has feelings for Navid.
Liam experiences some symptoms of post-traumatic stress disorder while preparing to testify against Ashley, while Annie is furious when Naomi tracks down their half-brother Mark, a chef who owns a gourmet food truck. Silver is overbearing with her surrogate Michaela, whom Dixon discovers has an amazing singing voice.
Naomi and Max see a marriage counselor to decide if they are going to stay married, while Teddy tells Silver he won’t ruin her chance to have a baby if she agrees to his terms. Navid uses Liam’s celebrity status to help him get into an elite secret society and Annie rushes to tell Riley her true feelings before he undergoes an experimental surgery.
Annie experiences an alternate reality about what life would have been like if she had stayed in Kansas, including being engaged to her high school boyfriend. In the alternate world, Dixon becomes a massively successful hip hop artist who no longer has contact with his family, while Adrianna is a washed-up actress and Hollywood’s bad girl. Naomi is a real estate agent, and Teddy has not revealed his true sexual orientation.
Annie and Vanessa search for Liam after discovering that Ashley was falsely posing as his studio-hired bodyguard. Needing a break, Naomi goes on a road trip with Adrianna, only to have her wedding ring stolen. Meanwhile, Dixon fails to convince Megan he is over Adrianna.
90210 revolves around several students at the fictional West Beverly Hills High School, including new Beverly Hills residents Annie Wilson and Dixon Wilson. Their father, Harry Wilson, has returned from Kansas to his Beverly Hills childhood home with his family to care for his mother, former television and theater actress Tabitha Wilson, who has a drinking problem and clashes with his wife Debbie Wilson. Annie and Dixon struggle to adjust to their new lives while making friends and yet adhering to their parents' wishes.