Dylan's long-estranged, beatnik, zen-freak mother Iris, whom he can't stand, comes for a visit from Hawaii, apparently to stay, which causes him to return to drinking which soon lands him in trouble at a local billiards club after hustling some pool sharks. Brandon tries to help Dylan deal with the situation, but Dylan is too blinded by his ego and pride to accept. Of the rest of the Walshes, only Cindy finds Iris McKay fascinating and free-spirited, while Brenda and Jim find Iris just plain weird. Meanwhile, Steve and Donna decide to play the stock market. But Kelly disapproves and accuses Donna of wasting her money.

Dylan's estranged mother, Iris, returns to Los Angles which resurrects old family hostilities for she doesn't trust Jack with handling Dylan's trust fund, as does Jim. Brandon continues gambling and splurges his winnings on skis and a new car stereo. Meanwhile, David and Steve meet with the eccentric Icon Records Company president Curtis Bray, who tells David that he will give him a recording deal only if he fires his personal manager Steve. Brenda spends the entire weekend in her bedroom moping about her lost relationship with Dylan, while dreaming evil dreams on doing physical harm to Kelly whom she unfairly blames for her and Dylan's breakup. Also, Andrea goes to a luncheon for Yale acceptances where meets her old friend Jordan Bonner.

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.

On the day of graduation, the gang thinks back about their most memorable moments from the past three years. Andrea delivers her commencement address and everyone celebrates. Dylan also has a mysterious encounter with his late father who advises him that he doesn't need to go to college to prove himself. Dylan instead asks Kelly to take a trip through Europe with him for the summer. Steve also decides to go to California University to be near his friends, while Brenda decides to to back to college in Minnesota. The night of graduation, they all meet in the Hollywood Hills near the big Hollywood sign to create their logo on the sign for the whole city to see to remember them for the years they had at West Beverly High School.

The Walshes welcome Valerie Malone, a young and charming family friend from Buffalo, who moves into Brenda's room after she leaves for England. But unknown to everybody, Valerie is secretly revealed to be a manipulative, cynical and callous woman with a taste for drugs and hard liquor. Meanwhile, Donna returns from her summer stay in Texas and claims that she's over with David, who's doing a video for his film class about his travels during the summer. But that evening, Donna has an emotional breakdown when she runs into David at a nightclub. Steve returns from his summer vacation in Hawaii and decides to pursue Kelly, unaware that she's involved with Brandon. Dylan returns from his summer stay in Baja, Mexico and is revealed to have gone back to drinking since learning that Kevin and Suzanne have swindled him and skipped town with all of his money, and Erica. Also, Andrea and Jesse finally take their new baby daughter, Hannah, home.

When Dylan is put in a coma after a car accident while driving under the influence of heroin, bizarre near-death dreams he has mirror his fight for life which involve his drug dealer, his high school principal Mrs. Teasley, Kevin, Suzanne, Erica, Valerie, the Walshes, and his own long-dead father, Jack. Meanwhile, Steve is bothered by the appearance of his annoying and overbearing father, Rush, at a flag-football tournament as part of the KEG sports weekend.

Brandon and Dean Trimble are caught in the middle of a conflict when several Jewish students, including Andrea, protest the scheduled campus appearance of a controversial, anti-Semitist, African-American orator, in which the demonstrations and near-riots disrupt Kelly's photo shoot for the magazine. Meanwhile, Donna plans a party for Ray's 25th birthday. In the hospital, Dylan spends the time talking with his mother Iris, while his drug dealer pays an unexpected visit and threatens him not to tell the police about their business.

Donna's snobbish mother, Felice, puts Ray's feelings for her daughter to a test by offering him money to stop seeing her, while Ray's alcoholic, chain-smoking, redneck mother, LuAnn, goes Christmas shopping with Donna. Differing family traditions cause tension between the Catholic Jesse and the Jewish Andrea. Clare introduces David to her father during a faculty Christmas party who finds common ground with him over their love of music. Meanwhile, Dylan goes to his old friend, Christine Pettit, from the FBI to help him find his stolen money. Unable to help Dylan, Christine then contacts an alcoholic, former FBI agent-turned-bounty hunter/private investigator, named Jay J. Jones (Jonesy), who contacts Dylan on Christmas Day and offers to track down his money in exchange for getting a full share of it. Brandon is left alone to care for the recovering Kelly when Jim and Cindy leave town to visit Brenda in England and Valerie leaves to visit her mother in Buffalo. Also, Nat hosts a special holiday feed-the-homeless dinner at the Peach Pit.