Acting as a "big brother" to a 10-year-old boy, Brandon is asked to keep a secret that needs telling about his single mother's physical abuse. Meanwhile, Kelly fears a familial connection to David when his father, Mel, and her mother, Jackie, begin dating. So, Kelly becomes determined to keep them apart. Also, Brenda can't keep the absent Dylan from her thoughts while he is in Hawaii visiting his mother.

On Scott's 16th birthday, his mother gives Donna and David the responsibility of rounding up people for his birthday party to save it from being a social disaster.

Steve arrives in Albuquerque, New Mexico and tracks down his grandfather, Al Brown, a diner owner. Al explains that his daughter gave up Steve because she was very young and wanted him to have a good home. He sadly reveals that Karen Brown died in a car accident many years ago. Steve leaves flowers at her grave, and convinces an eccentric Santa-like charter pilot to fly him home for Christmas. Back in California, Cindy is depressed about her first Christmas in Beverly Hills. She invites the kids' friends and their families for Christmas Eve dinner, but everyone has other plans. Brandon visits Emily in a psychiatric hospital, where she is doing very well. Meanwhile, Brenda begins work at an upscale clothing store. A mysterious old man steals a Santa Claus suit from Nat at the Peach Pit, and later shows up at the boutique store where Brenda works. She feels bad when her brass boss throws out the cheerful old man. After work, Brenda stops the police from harassing the old derelict wearing the Santa suite and invites him over for dinner, much to the wariness of Jim and Cindy. Also, Dylan goes to see his father in prison, and talks with the same Santa. Elsewhere, Kelly's mother, Jackie, is furious when David's father, Mel, backs out of Christmas Eve plans because his estranged wife asked him to come over with David. Samantha, Kelly, Jackie, Andrea, David, Mel, Donna, Dylan, and Steve all show up at the Walsh house for dinner and caroling. The old man in the Santa suite gives everyone presents and describes his lonely life: his children are grown and his wife died a year earlier. He thanks Brenda for her kindness and generosity, then mysteriously disappears as footsteps are heard on the roof.

Andrea fights with the school board to lead a campaign to have condoms distributed at West Beverly. But not all of the gang and their parents are happy about it since Donna's uptight, influential, and fiercely conservative mother, Felice, is opposed to any sex education in schools and has the PTA rally around her for her own self-serving support. Meanwhile, Brenda writes a term paper about her experiences with her pregnancy scare, which upsets Dylan who feels his privacy should be kept private. Also, David wants to plan a special evening with Donna.

When Kelly's mother Jackie, divulges the secret that she's pregnant, misunderstandings and grapevine talk between Kelly, David and Donna threaten to end the relationship between her and David's father Mel. Meanwhile, Nat takes Brandon, Steve and Andrea to the racetrack to bet on some horses due to Andrea's "power" to see the winner, and Dylan plans a special Valentine's Day for Brenda, of donating blood.

After missing curfew a few too many times by staying over late at Dylan's house, Brenda is grounded and is forbidden to go surfing with him in Mexico for the weekend. But Brenda secretly decides to go anyway and asks Kelly and Brandon to help cover her tracks. Meanwhile, Kelly becomes acquainted with Jake Hanson, a handyman and an old friend of Dylan's, who eases her fears over her mother deciding to marry David's father and both become attracted to each other, despite their age differences.

Brenda faces the wrath of her parents after her disastrous return from Mexico. In a desperate attempt to keep Brenda and Dylan apart, Jim bans him from coming over to their house which only alienates Brenda even more, especially when Brandon and Kelly take out their troubles on Brenda over lying for her during her surfing trip. When the Taylor house suddenly floods from a ruptured water pipe, the Walshes reluctantly agree to host Mel and Jackie's wedding at theirs. Meanwhile, Kelly mourns the departure of Jake when his job at the Taylor house is done. But he returns during the wedding and things heat up between them.

Dylan and Kelly decide to keep their romantic liaison a secret when Brenda and Donna return from Paris. During a welcome-back party for Brenda and Donna, Brenda confides in a guilt-ridden Kelly that she sees that something has changed about Dylan while she was away. Meanwhile, Brandon discovers that Brooke is not the girl of his dreams after he sees little amusement in her repeated racist and stereotypical comments. Also, Steve finally lands a gig for David at the end-of-the-summer clambake at the beach club.

Dylan's father, Jack, is finally released from prison to enjoy his son's company, and sets eyes on his trust fund. David doesn't know where he will live after his father moves out of Jackie's house. Meanwhile, Brandon's addiction to gambling intensifies when he starts using his own college money. Andrea decides on a new look for herself by her hair dying it red and trading her eyeglasses for contact lenses. But other than Donna, no one seems to notice Andrea's make over. Also, Dylan finally chooses Kelly over Brenda who is worsened after they tell her about their summer fling they had while she was in Paris.

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.

Following a little advice from Gil Meyers, Brandon and the rest of Donna's friends join forces to help her in a major school protest when she is suspended from school and is threatened with not graduating for getting drunk on Senior Prom night.

Dylan considers buying a gun after his new car is stolen from him at gunpoint. Meanwhile, Brandon's sociology professor Corey Randall asks him to tutor the university's basketball star, D'Shawn Hardell; Andrea and Dan mull over going public with their affair; Brenda and her parents are invited to lunch at Stuart's parents' house in Bel Air as Brenda and Stuart's romance really takes off.

Cindy and Jim throw a party for their 20th wedding anniversary. As Stuart and Brenda's affair grows, he proposes marriage and she willingly accepts. Meanwhile, Brandon falls for an anthropologist grad student named Lucinda Nicholson. A paranoid Dylan buys a gun from a street dealer and almost shoots Brandon. Andrea tells Kelly that she has doubts about her affair with Dan after he tells her about his non-belief in marriage; then Andrea meets Jesse Vasquez, a charming Latino barman, at the party. Mel asks David to look after baby Erin while he heads off to Mexico with his girlfriend.

Brenda is bothered when Stuart tells her that his parents want her to sign a prenuptial agreement; Jim also finds out about Stuart's prenuptial papers and asks Dylan to look into Stuart's background. Meanwhile, David and Kelly grow more hostile to each other when they are caught in the middle of Mel and Jackie's custody battle for Erin. On his first dinner date with Lucinda, Brandon discovers that she is married... to his sociology professor. Guilt plagues Steve he does a favor for Sears and his frat buddies to bed blind date Laura Kingman, a professional college dancer.

The Walshes trip to Hawai'i doesn't go as planned when their plane is turned around due to technical problems. A woman claiming to be Jack McKay's mistress shows up on Dylan's doorstep with her daughter in tow. David's sexual frustration leads him to be hostile to Donna. A lonely Kelly cracks her tooth on candy and calls Mel for dental advice. Jesse takes Andrea with him to church for midnight mass. The characters all flash back to previous Christmases over the course of the episode.

The side effects of David's burgeoning drug habit cause him to fall asleep in the park whilst babysitting Erin and she goes missing. Brenda, Donna, Brandon and Steve head out of town on a ski trip where Donna meets a handsome ski instructor. Dylan finds himself slightly out of his depth when Erica gets her first period after their swimming lesson. Jim's background check on Suzanne yields some unexpected results and Dylan confronts her upon her return to Beverly Hills. Andrea receives a surprising medical diagnosis.

Donna tries to make up with David, whose increased drug use turns her away. David also steals $150 from his father to buy more amphetamines for himself. When his drug dealer is arrested later, he finds himself in possession of a huge stash of narcotics and calls on Dylan for help. Meanwhile, Jesse and Andrea meet with her grandmother to get her blessings before their wedding and reception at the Peach Pit. A dangerous affair begins between Brandon and Lucinda, who shows her true colors when she starts teaching her anthropology class of human sexuality and preaches the need for multiple partners, seeing sex as her personal weapon. Brenda gets a surprise visit from a long-absent Stuart on Valentine's Day.

Kelly's disapproval of her mother's return to modeling increases when she learns that her baby sister Erin is involved. Meanwhile, the Walshes finally learn that Dylan is broke when the proposed Peach Pit expansion leads to an exposure of his finances. Valerie, still smearing with both anger and pity after catching Dylan cheating on her, confirms to them that Dylan is bankrupt. Jim then offers Dylan financial assistance. But the growingly misanthropic Dylan is too far gone to accept any sympathy and rudely blows off Jim. While Donna has trouble balancing the affections of both Griffin and Ray, she sees Griffin's sleazy other side when he whisks her away for an overnight trip to Catalina Island and attempts to seduce her. David's love experiment by handcuffing himself to Clare's bed to win her affections backfires when her father shows up and takes her out to dinner, leaving David alone. The next morning, when Steve and David come over to Dylan's house to talk about the Peach Pit After Dark expansion, they find Valerie in bed with Dylan. Steve, being the person he is, draws the wrong conclusion and responds by punching Dylan in the face.

Lenny becomes an outcast when he is suspected of the campus rape despite his protest of innocence which prompts him to ask Brandon to help him prove his innocence. At the same time, the real rapist stalks an unsuspecting Donna and violently attacks her in the beach apartment. Meanwhile, Dylan accidentally becomes privy to Andrea's affair with Peter when he sees them together at Charlie's motel. When Andrea decides to leave Jesse to be with Peter, he reveals that he doesn't share the same views as she. Elsewhere, Valerie asks Steve to help secure the rock group "The Flaming Lips" after she cancels Ray's bookings, and Donna wrongly blames David for Ray's departure after Valerie lies to her that David is the one responsible for Ray leaving town.

Brandon and Clare have the same bad dreams involving "Jeopardy" host Alex Trebek and announcer Johnny Gilbert while competing with each other and Andrea for a spot in the show's college tournament. After learning from Andrea about her affair, Jesse moves in with Dylan and talks about the possibility of divorce while Dylan tries to reason with him to make up with her. Meanwhile, the reconciliation of Mel and Jackie gives David hope of reuniting with Donna whom he still has feelings for.

During spring break, Donna visits Ray now living in Portland, Oregon and David tags along to visit his mother only to learn that she has disappeared. So David, along with Donna and his father, Mel, follow a strange trail of the past to find her, while Ray begins to show increasingly signs of jealousy over Donna helping David find his mother. Back in Beverly Hills, Dylan undergoes hypnosis by a therapist in his research to find ideas for a screenplay for Charlie, while Valerie considers and gets a tattoo for herself.

After David's mother attempts to kill herself, it turns him into a recluse and it brings back bad memories for Valerie over her father's suicide. Meanwhile, Toni invites Dylan and his friends over for dinner at her father's mansion where Toni's bodyguard, Bruno, confronts Dylan that he and Marchette know all about him and his father. Also, Brandon finally negotiates a date with Susan, but dating and newspaper politics sometimes don't mix. Elsehwere, Nat and his chef, Willie, try to catch an elusive mouse at the Peach Pit that's hurting their business, until Donna comes to their rescue.

Brandon and Mark find the perfect newscaster - a student named Tracy Gaylian - for the campus TV station, but she panics and gets drunk prior to her debut. Meanwhile, an accident with Jimmy gives Kelly a big scare about having AIDS. Mel withdraws David's financial support after learning from Donna that he dropped out of college to concentrate on his film making career. Elsewhere Valerie continues her secret affair with Kenny, who must find the time to be with her.

Steve declares war by trying to find a date for himself just to make Clare jealous when she starts dating another guy, named Dick Harris, whom he can't stand. Meanwhile, Donna's new fireman boyfriend, Cliff Yeager, who saved her life during the brushfire, assists her at her sorority's Halloween Haunted House bash. At the reopening of the Peach Pit After Dark, Kenny does not attend, prompting Valerie to resort to her devious tricks again by asking for $100,000 so she can keep away from him. Also, Brandon tries to get closer to Tracy while Kelly hits on Mark.

David's gets a huge windfall when he inherits $250,000 after his grandfather dies. But it causes a rift with his father Mel over how to use it when David lets the thought of wealth go to his head. Kelly extends an olive branch to Valerie after learning from Steve over her condition, but Valerie must keep the fact that she really isn't pregnant under wraps at any cost. Meanwhile, Steve rashly challenges Dick to a crew race, much to Clare's anger. Tracy makes an overture to Brandon to appear with her on a presidential debate. Also, Cliff takes Donna on a camping trip where he tells her of his future plans, not involving her.

Kelly delights in telling Brandon about Valerie's pregnancy and abortion, and also shares her doubts about Val's story. Brandon goes to see Kenny, who portrays himself as the innocent victim caught in the web of an evil vixen. He tells Brandon that he paid Valerie $100,000 to stay away. Brandon threatens to throw Val out of the house unless she returns the money. Valerie plans to move out, but instead returns the money following a talk with Tracy. She confesses to Brandon that she was never pregnant, and insists that she cannot live up to his moral expectations. Mel, worried by David's newfound wealth, asks Donna to keep an eye on him. David goes on a wild spending spree, and later shows up at Donna's apartment in the middle of the night after swimming in the ocean. David offers to help out the financially strapped Valerie by purchasing half of the club. Steve impresses Clare with his dedication as he trains for the crew race. His team barely loses, but Clare decides that she wants him back. Kelly comes clean with Mark about her past drug problem.

During an argument with Donna in the student union, David throws a tantrum and cuts his hand on a glass. He must see a psychiatrist after displaying hostile behavior toward the ER staff. Mel agrees with the doctor's recommendation that David be held 72 hours for observation. David is diagnosed with a mild form of manic depression. His mother comes to see him and advises him to moderate his behavior; he will not require medication if he seeks therapy and stops drinking. David thanks Donna for her support and they decide to get back together. Steve faces plagiarism charges; Professor Randall, who assumed control of the independent study course after returning to CU, recognized Brandon's writing. Randall still holds a vendetta against Brandon and brings collusion charges against him. Kelly and Mark's plans for a romantic weekend getaway are foiled by a lost reservation. They finally secure a motel room, only to come down with food poisoning. The gang helps Willie build a house that his family will receive from Habitat for Humanity. Val displays construction skills as a result of working with her contractor father, but hints to Clare that she has few happy memories of her dad. Everyone eats Thanksgiving dinner inside the unfinished house.

Valerie and Kelly are reluctantly paired in a Christmas gift exchange, where Valerie goes shopping with Tracy to find the certain gift. Kelly gets a big surprise when she meets Joy, a half-sister from her father that she never knew existed. Meanwhile, Steve and Clare find themselves playing holiday matchmakers to his mother and her father during a Christmas faculty party. Also, David tries to get on the good side of Donna's conservative and domineering mother, Felice, who offends everyone again. Elsewhere, Brandon and Tracy share their exchange of gifts.

On the day before commencement, Kelly becomes determined to oust Valerie from the Walsh house (and town) and pressures Brandon to do so. Meanwhile, Donna decides it's time to move up to a new level of romance with David after getting advice from her grandmother. Steve plans to pull the "best senior prank ever" with some help from his frat brother Muntz, as well as David.

On the day of graduation, a broke and lonely Valerie disrupts Kelly's plans when she takes off on a mindless spree causing Brandon to delay the ceremony to look for her. Kelly's father, Bill, throws a 1920s nostalgic post-graduation party for the class and has the The Cardigans band perform. He also tries to make up with Kelly, who continues to push him away. Steve's stepbrothers, Ryan and Austin, show up for festivities where Ryan is drawn to Kelly's half-sister, Joy. Also, Steve's plans for Clare derail due to her decision to move to Paris with Chancellor Arnold, which leads to Steve and Clare breaking up for good.

After throwing David out of the beachfront apartment, Donna meets with Noah who takes her on sailing, then rescues a bankrupt David from his loan shark who wants a huge payback, with interest. Meanwhile, Erica runs away from Brandon and Kelly to go back to her pimp, Riggs. After a heated confrontation, Erica comes to her senses and helps Brandon write her life story for his newspaper, but Brandon soon finds himself in trouble when he refuses to reveal his source to an A.D.A. who wants to prosecute Erica's pimp. Carly persuades a reluctant Steve to take a paternity test to find out if Jodi, his former flame, is really pregnant with his baby.

With a few hours before Brandon and Kelly's wedding, they continue to feel uncertain about the path they are on. Jim and Cindy Walsh arrive in town from Hong Kong to help plan Brandon and Kelly's wedding. Meanwhile, Valerie finally decides to get an AIDS test after Johnny confesses to her that he happens to be HIV-positive, and she asks David to come along with her for emotional support. Steve becomes dateless for the wedding when Sarah decides to go back to her husband after witnessing her friend's messy break up. After the caterer, Jacob, saves Donna's life, Donna agrees to go on a pretend date with him to make his ex-girlfriend jealous. This makes Noah jealous.

Kelly's car did not actually break down...she received a call from Dylan to meet her at a diner because he was depressed and was thinking about taking drugs again. Kelly went to meet him, and parked on a side street. The attacker started to follow her. He then pushed her into an alley and assaulted her.

David's brash, new radio persona received flack from Donna and others, but also high ratings. Meanwhile, Matt and Kelly clash when he goes to court to try to overturn the death sentence for a convicted rapist-murderer, while Kelly also gets a visit from the parents of her rapist. Noah and Gina continue running their secret gentlemen's club in the After Dark, but the place attracts the wrong attention when the police raid it after several nuisance complaints, arresting both Noah and Donna. Gina slips away with David's father, Mel, who's also in attendance. Steve and Janet clash over their plans for Halloween as Steve wants to decorate the house and Janet wants to appear in a band that's playing at a 1980's Halloween party at the After Dark.

Kelly and Dylan are asked to be the godparents of Steve and Janet's baby and so they travel to Ojai to plan their approaching wedding. There, Kelly and Dylan question their link to each other. Meanwhile, Steve hesitates to trade in his beloved Corvette for a mini-van. But then David takes matters in his own hands when a shady performance artist, named Marta, offers $28,000 for Steve's car. A homeless man's death affects Donna which sets her and Noah out to learn the history of the anonymous man. Matt's determination to overturn the death sentence for his imprisoned client continues to anger Kelly. Also, Gina begins blackmailing Mel Silver for $1,000 a week in order to remain silent about his philandering. At the end, when the ever greedy Gina demands even more money from Mel for her silence, he refuses to pay. So, Gina does not hesitate to make an anonymous phone call to Kelly's mother.

David and Donna announce their engagement in which all of their friends rush to give them the perfect wedding with Donna's mother, Felice, and Kelly's mother, Jackie, taking over the arrangements and Nat catering for the ceremony and agreeing to escort Donna down the church aisle. Meanwhile, Steve asks Janet to help him form their own publishing company so they both can have time for baby Maddie. Noah returns to Ellen and tells her that he has decided to give their relationship a second chance. At Donna's pre-wedding party, Kelly, Janet, Felice and Jackie are in attendance as well as friends from their past who include West Beverly High principal Mrs. Yvonne Teasley, as well as Andrea Zuckerman and even Valerie Malone. At David's bachelor party, Steve, Noah, Dylan, Nat, and David's father Mel attend the gathering as well as Steve's stepbrother Ryan and former KEG fraternity brother Munz, except for Brandon Walsh who sends his regards to everyone via videotape. The day of the wedding goes without a hitch and at the end, Matt shows up briefly to tell Kelly that he has decided to move back to New York, and she goes back to try to renew her relationship with Dylan.