The Walsh Family moves to Beverly Hills, where the twins, Brenda and Brandon, meet new friends during their first week at West Beverly High School; Brandon falls for the most popular girl in the school while Brenda pretends to be a college student to romance a young lawyer.

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.

After David proposes marriage to Donna, both of them contemplate the matter and finally make a big decision. With Janet's career as a junior editor for the new owner of the Beverly Beat taking off, Steve become conflicted about being an unemployed stay-at-home father for baby Maddy. Kelly, while trying to open her independent public relations company, must make her own final decision on marrying Matt to console him after he learns that his brother in New York has suddenly died, and an uncertain-of-himself Dylan after he gets his college diploma. When Kelly tells Matt that she cannot marry him out of uncertainty, he lets the slip about his one-night stand during the desert road trip. Also, Noah contemplates commitment to Ellen and her daughter, but when he feels he's not ready, he breaks up with Ellen for good.