In the season four premiere, gang from Beverly Hills have graduated from high school. Naomi has spent the summer dealing with the shocking news of her pregnancy and quickly discovers she doesn’t have the status at college that she did in high school. Annie receives some unexpected news that keeps her in town, while Liam returns from his summer away ready to commit to Annie. Dixon finds himself without a roommate or a place to live, while an unexpected visitor tests Navid and Silver’s relationship after they move in together. Adrianna comes back to town looking for redemption, which she soon learns will be hard to earn back. Ivy and Raj struggle to deal with Raj’s health getting worse, while Teddy struggles with coming out to his family.

In an effort to re-gain her status, Naomi rushes a popular sorority, where she, along with Annie go through sorority games. Annie finds out a shocking secret about new guy Jeremy that could affect her future. Liam decides to keep the bar he bought on a whim and has a surprise guest from Alaska come into town, while Dixon finds an unlikely roommate in country boy Austin, which could lead to trouble. The search for Navid's sister Leila forces Navid and Silver to enlist in Adrianna for help, much to the dismay of Silver.

After making an enemy in sorority president Holly, Naomi finds unusual allies who help her get revenge. Annie, short on money for sorority dues, must figure out a quick way to come up with the cash. Liam and Jane get closer, while Adrianna reveals a secret that causes Liam to look at her in a different light. Ivy becomes increasingly frustrated with her friends and lashes out at their lack of compassion, while Navid must deal with his uncle coming into town and trying to undermine Shirazi Studios.

Navid surprises Dixon with some studio time to apologize for messing things up with a music producer, where Dixon feels the pressure to create a hit song. Naomi plots revenge to take down rival Holly and her sorority during the Greek games, which requires Austin's help, much to Naomi's dismay. Silver directs a disastrous commercial for Liam's bar, while Ivy feels torn between her relationship and her friends.

Silver is asked to make campaign videos for political candidate Marissa Harris-Young who is running against Teddy’s Uncle Charles for public office. Teddy runs into an old flame and Annie gets stuck with Leila during an important date. A surprise visitor threatens to tear Liam and Jane apart, while Naomi can't shake her growing feelings for Austin during a party to encourage students to vote.

Liam gets offered a modeling job after an agent sees the commercial for his bar, while Annie finds herself starting to fall for an unlikely guy. During a charity talent show event to raise money for an experimental cancer treatment for Raj, Naomi is determined to win the contest in order to show up Austin's out-of-town visitor Sally. While working on his music, Dixon pushes his limits and starts spiraling out of control, which forces Adrianna to confront him.

Naomi has to work with her arch-nemesis Holly to throw a campus costume party, leading to unfortunate consequences. Navid's plan to bring down his Uncle Amal is threatened, while Silver discovers that political candidate Marissa Harris-Young is not who she seems. Meanwhile, Adrianna handcuffs herself to Dixon in an attempt to get him to stay sober and Annie must decide if she wants to give Patrick another chance.

The gang heads to Las Vegas, where Naomi meets Austin's dad, country superstar Judd Ridge. The guys run into a celebrity at the pool, where Liam gets invited to play in a celebrity poker tournament. Teddy and Shane decide to tie the knot, while Dixon and Adrianna get closer. Meanwhile, Navid sees an opportunity to take his Uncle Amal down.

Silver’s video of Teddy's Vegas wedding is leaked to the press, and has damaging effects on his uncle’s campaign. Liam’s modeling career is taken to the next level by Shelia and Annie is determined to help Dixon, even though the help he needs comes at a high price. Meanwhile, Ivy and Raj decide to plan for the future.

Dixon tries to pursue a relationship with a resistant Adrianna, while Ivy and Raj’s arguing takes a toll on their relationship. Liam plans a holiday dinner for the gang, and an unexpected guest shows up. Meanwhile, Naomi goes to extremes to prove her love to Austin.

Dixon struggles with temptation as he tries to make his way back into the music world, while Annie confronts Jeremy, who stands in the way of her inheritance. Naomi and Holly embarrass themselves in front of Janice Dickinson at a fashion show, while Navid reaches a breaking point with his uncle. Meanwhile, Teddy makes a big decision that upsets Silver.

Naomi is asked by her new party planner boss Rachel to oversee her arch-nemesis Holly’s birthday party, while Annie breaks into Jeremy’s apartment in a desperate attempt to get the proof she needs to keep her inheritance. Navid finds trouble after going with his Uncle Amal to make a deal with a potential buyer, and Liam discovers shocking news about Annie.

Naomi embarrasses herself in front of her boss Rachel in an attempt to get over her break-up with Austin. Dixon and Adrianna are booked to perform at a club, where they realize that working together might be a bad idea. Meanwhile, Silver takes her relationship with Greg to the next level and a party Annie throws ends up being a disaster because she is too distracted by Liam's new relationship.

Naomi is determined to fix the relationship between her boss Rachel and her daughter Holly, which forces Holly and Naomi to work together. Greg asks Silver to move to New York with him and Navid finds out some shocking information about Greg’s daughter. Annie discovers Liam’s girlfriend Vanessa might have been involved with his motorcycle accident.

Annie has to make a decision that could expose her work as an escort when Dixon gets arrested in connection with a fire at a sorority house. Adrianna and Silver attempt to put their past behind them, which results in disaster for Silver's relationship with Greg. Vanessa helps throw a party to re-launch Liam's bar, where the All-American Rejects perform.

In an effort to put her inheritance to good use, Annie volunteers to organize a big charity fundraiser. When Naomi takes drastic measures to land her first event-planning client, her big plan back-fires. Meanwhile, Silver realizes she still has feelings for Navid, and Vanessa vows to make Liam a huge star after his agent drops him.

Naomi’s sister Jen arrives with her son for a surprise visit. Adrianna and Dixon land a meeting with a major movie producer to discuss music on his next film, but are sabotaged by Vanessa. Meanwhile, Silver gets accepted into New York University and Ivy attracts attention in the underground scene when she switches to a less conventional style of art..

Naomi is convinced that Annie’s new business partner P.J. is the perfect man for her, but discovers her sister Jen is also interested in him.. Adrianna and Dixon land a spot in a music festival, where Train performs and a record executive offers Dixon a recording contract. Adrianna tells Liam her suspicions that Vanessa staged the near drowning incident.

Dixon collapses while arguing in the recording studio with Adrianna. In the hospital, they run into Liam who is with Silver to support her during a test to detect if she has the breast cancer gene. Ivy finds out Raj still has cancer and is in the hospital, while Annie meets a new guy Caleb and discovers he is a priest.

PJ proposes to Naomi and Annie discovers he needs to get married in order to get the rest of his trust fund. Dixon confesses to Navid that he signed a record contract but admits he did not tell Adrianna because the label didn’t want to sign her. Dixon also accepts a gig to play back up for Haley Reinhart, but doesn’t tell Adrianna. Liam asks Vanessa to move out and discovers she has emptied their joint bank account.

Naomi’s friends worry that she is rushing to get married, so Naomi and P.J. decide to throw a small party so everyone can get to know him. Austin returns to Los Angeles and offers to be Adrianna’s new manager, suggesting she give country music a try. Caleb is concerned Ivy might not be emotionally stable, while Annie finally admits to Caleb that she is falling for him. Meanwhile, Silver feels conflicted about her feelings for Navid who is back in town.

Navid suspects that Liam and Silver hooked up so he decides to confront Liam on the red carpet of a movie premiere. Annie and Caleb fight their attraction to one another but finally give into temptation. Meanwhile, Naomi has been hired to plan the wedding of an heiress and discovers she knows the groom a little too well, and Austin enlists his dad, Judd Ridge to be help launch Adrianna’s country career.

A reluctant Naomi tries to sabotage the bachelorette party she has to host for Max’s fiancée Madison, where Madison’s childhood crush, Nick Carter, makes a surprise appearance. At Max’s bachelor party, Liam and Navid get into a fight over Silver and the evening comes to an end with people at both parties getting hauled to jail. Meanwhile, Ivy blames Annie and Caleb for Diego having to go on the run.

Naomi shocks everyone when she announces she won’t be able to oversee Max’s wedding because she has accepted a job in New York and will be leaving immediately. Teddy comes back to town and Dixon rushes back from touring to give his relationship with Adrianna another try, then fails to show up at their meeting spot. Meanwhile, Silver feels like she has to choose between Navid and Liam and makes a life-changing decision.

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.