Kelly's father Bill Taylor, arrives in town apparently to stay, while at the same time, she again catches Colin sniffing cocaine. Joe makes a professional call on Donna's cardiologist father who discovers that Joe may have a certain heart disorder. Meanwhile, Nat refuses to participate in Steve's film festival honoring Roger Corman after the gang sees him in one of Corman's movies from 1972 titled 'Unholy Rollers'. Things take a turn when Joan Diamond, a former actress and Nat's old fiancée, arrives for the festival. Also, Brandon continues to be jealous of Susan's ex-boyfriend Jonathan when he phones to speak to her and Brandon doesn't leave a message for Susan.

Steve becomes depressed and frustrated with his father when Rush doesn't approve of the quick and easy future Steve has planned following graduation from C.U. Clare tells him that her father wants her to move to Paris with him after graduation and wants Steve to come with her. Meanwhile, Kelly's father, Bill, arrives in town for another visit and meets with Valerie, who tells her that Derrick Driscoll is actually an embezzler who just ripped off all her money that she invested. Kelly receives disturbing medical news that she may not be able to bear children. Also, Donna flakes out on her last final exam with Professor Langley.

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.

Kelly objects to the decision of a Special Services person when the abandoned baby is placed with a gay couple. Meanwhile, Brandon and Steve and Janet quarrel over running cigarette ads for their failing newspaper in which Brandon threatens to quit, while Steve continues to pretend that he's Ted in order to please his pen pal friend Jill. Noah asks to finance Donna's marketing of her own designs for another fashion company. Also, Valerie deals with her long-estranged mother, Abby, who arrives back in town for a visit and hits it off with Kelly's father, Bill, who has been paroled from prison. Elsewhere, David becomes intrigued by his new neighbor Woody Sloan, a former rock star.

Valerie and Kelly reluctantly join forces to attempt to break up Valerie's mother, Abby, and Kelly's father, Bill, after they announce their engagement at Valerie's birthday party. Brandon interviews for a job at a major daily newspaper and is hired on the spot, but he discovers there's a catch: Brandon must fill in as a scab for other agency reporters going on strike. Meanwhile, at the Beverly Beat, Janet begins to complain to Steve about being overworked and underpaid. Steve sets off in search of Jill's real penpal, Ted, to introduce them to try to mend the hostile situation he started. Noah goes too far in helping Donna with her work, bribing a local fashion company to set the stage for her designs and purchases.

In the week before Kelly and Brandon's wedding, they experience a barrage of conflicting emotions about heading to the altar. Meanwhile, David pressures Valerie to get an AIDS test after she confesses to him about her one-night stand with Johnny. Valerie is reluctant to do so, and provokes conflicts with everyone except David, for whom she still has feelings. Steve becomes nervous about losing Sarah when she begins marriage counseling with her estranged husband. Also, different views of marriage divide Noah and Donna; he tells her that he does not believe in marriage.

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.