David and Donna visit her paternal grandmother, Celia Martin, who tells them the story of her husband who was the only one true love of her life during the 1940s. Meanwhile, Valerie meets and befriends Rob Andrews, a young and new rising actor in Hollywood. Kelly befriends an 11-year-old boy, called Joey, she finds camped outside her apartment, whom she suspects is a runaway. Also, Steve asks Brandon, Tracy and Clare to help him with filming an infomercial as a class project and literally gets into a sticky situation regarding the product's true nature.

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.

Donna's grandmother is hospitalized after telling Donna that her soulmate is David, who moves out of the Valerie's room at the Walsh house and into Carly's vacant house until he can afford a more inexpensive place. Meanwhile, Kelly alerts Brandon to a potential story about a recently paroled ex-con who explains to Brandon about the mistakes he made that changed his life, which Brandon realizes parallel his own. Steve coaxes Brandon into a double date with two women who he ran into at the Peach Pit, unaware that the women are not who they appear to be. Valerie brings a record executive to the After Dark to hear David and the band, Jasper's Legend, perform their debut. But Valerie is hurt after David tells her that the love song he wrote was about Donna, not her.