Brandon goes undercover for the Blaze to try and expose steroid use within the school's track team, and finds that Steve is involved after teammate Kyle tips Brandon about it. Brandon is then caught in a dilemma of how to expose the drug use without hurting Steve along with everyone else. Meanwhile, Brenda gets into a minor car accident with a con artist woman who's out for money.

As the gang of West Beverly begins its senior year, Andrea accuses the new reading teacher and Blaze faculty advisor, Gil Meyers, of sexism when he names Brandon the new editor of the school paper. Meanwhile, David discovers that his summer fling Nikki, is a transfer sophomore student and Donna's new friend. Brenda and Steve become "senior buddies" to two freshmen who are Sue Scanlon, the late Scott's younger sister who has two personalities, and Herbert, an intellectual type. Also, Kelly continues to be uncomfortable and jealous about seeing Dylan with Brenda.

During SATs week, Brenda tries desperately to quit the smoking habit she picked up while in Paris. At the same time, she talks a little too openly to Beth Nielson, a tabloid-TV reporter, about life in Beverly Hills, who twists her story and her friendships. Meanwhile, Nikki turns her sights on Brandon and tries to win his affections. An academic shortcut tempts Steve when a West Beverly alumni, B.J. Harrison, offers him the master key to the school. Also, Dylan visits his father in prison again who gives him some advice on his future.

After a West Beverly football game is canceled because of the gang violence at the opposing school, Brandon meets with Jordan Bonner, the class president from the rough South-Central school, who together they decide to make a stand by inviting some of the students from the school to a West Beverly High dance, being headed by Brenda and sponsored by Gil Meyers. Meanwhile, Kelly goes to meet with her long-absent father. Also, David gets a DJ gig at the dance and a groupie, who is Sue, much to Donna's jealousy.

Gambling addict Brandon multiplies his addition by hiring a school bookie, Jeff, in order to pay off $1,500 of losses to Duke who's now out to get Brandon. Meanwhile, David finally realizes the true nature of the music industry when Serge continues to ignore his hip-hop material and forces him to record a repetitive, syrupy ballad. David goes along with it, but Curtis Bray does not like the new tune and outright terminates David's recording contract. Finally seeing the egotistical, two-faced shark that Curtis Bray really is, and the self-serving hack Serge is, David leaves Icon Records and goes back to apologize to Steve for the way he treated him. Kelly's eating disorder worsens when she starts taking diet pills. Also, Andrea tries to ease Dylan's depression over his father's murder by asking him if she can do an editorial on him.

With the possible sale of the Taylor house, Kelly gives her mother and prospective buyers a hard time. David and Donna plan to throw Kelly a surprise 18th Birthday party at the Peach Pit. But things take a unexpected turn when the guests get an even bigger surprise from Kelly when she collapses due to an overdose of diet pills. Meanwhile, Steve badgers Brandon into joining him on a TV dating game show and Steve wins a date with an attractive girl named Celeste Lundey.

Voted the most beautiful senior at West Beverly, Kelly fears that no one's looking beneath her good surface, while she becomes hurt over Dylan not wanting to show her his finished editorial whom he shows to Andrea first. Meanwhile, Steve forgets he's dateless when he goes out with Brandon and his parents to a Lakers basketball game and is randomly chosen to win $10,000 for a half-court shot. Also, Brenda reconsiders her college choice of going back to Minnesota.

The Gang plans to go to Magic Mountain for Senior Ditch Day but plans change for Brandon, Dylan, and Steve when a Burt Reynolds fan club eats at The Peach Pit when Nat is sick. Everyone else heads to Magic Mountain.

Brenda and Brandon are dateless for the Senior Prom. A school announcement is made that any student caught at Senior Prom drinking, intoxicated or with illicit drugs will be suspended from school and prevented from graduating. Footballer Tony Miller asks Brenda to prom on the day of the event, and Andrea asks Brandon at the last moment after her date, Jordan Bonner, gets ill. Steve takes Celeste Lundey, while Dylan naturally goes with Kelly. Donna doesn't eat all day so that she will fit into her prom dress. She is hit harder by pre-prom champagne than the rest of the gang, appears to be drunk at prom, and ends up collapsing in front of Mrs Teasley.

With 24 hours until graduation, Andrea frets with Brandon over her coming valedictorian speech and her college choice of California University or Yale, as does Brenda with Minnesota. Meanwhile, Dylan gets a windfall when he inherits his trust fund worth $10 million, as well as another surprise visit from his eccentric mother Iris, while he reconsiders his college choice of Berkley or California University. On graduation day, David and Donna are the MCs at the Senior Breakfast gathering while Steve meets with the gang to create something to remember them by.

Steve invites Brandon to stay with him at a Malibu beach house, owned by one of his mother's industry connections. They throw a farewell party for Brenda before she leaves for college in Minnesota. Kelly returns from Europe, without Dylan, who has been rejected for acceptance into Berkeley. David seeks out affordable off-campus housing. Brandon has a surprise encounter at the beach house with Jill Fleming, daughter of the owner, who mistakes him for a burglar and threatens him with a can of mace. Andrea visits Gil Meyers and frets over her decision to stay in California for college instead of leaving for Yale.