Kelly and Donna invite Janet to move into the apartment. Janet tries to tell Steve that she is pregnant, but stops when he mistakenly assumes that she has gotten breast implants. When Janet finally reveals the truth, Steve becomes outraged that he had been kept in the dark for so long. He avoids Janet and whines about the situation to the other guys and Gina. Janet tells Steve that he can choose how much involvement he wants with the child; he is unsure of what to do. Kelly, Donna and the gang throw a surprise 24th birthday party for David at the After Dark. The uninvited Gina foils their plans by slashing her own tire and calling David for help. After patching things up with David, Gina takes him to the club and drops him off without spoiling the surprise. A young woman whom Dylan knows from his years at the hotel gets busted for drug possession. He pays for her legal services, and encourages her to get clean and find some direction for her life. He agrees to return to college if she also enrolls. Matt helps Kelly cope with her fear of physical contact.

Steve buys an engagement ring and practices proposals, often with Noah assuming the role of Janet. Dylan harasses Janet about her decision. The gang's attempt to arrange a reconciliation backfires. Janet insists that she loves Steve, but believes that his chaotic lifestyle would be harmful to the child. Steve later breaks down in tears and argues that his spontaneity does not mean that he cannot be a responsible husband and father. He surprises Janet with a proposal during her ultrasound, and she accepts. Dylan grows tired of living with Gina and suggests that she find her own place. He offers to spring for a hotel suite, but Gina opts to establish her independence. David's radio show becomes popular due to his abrasive tactics, including talking about Dylan's personal life and asking a woman out while on the air. Dylan goads David into providing details of the date to his listeners, and the woman dumps him. Donna recommends a new act for the club, failing to disclose the fact that the singer is Wayne's cousin. Noah is angry, but he and Donna soon get back together yet again. Kelly pouts about Matt's cynical attitude toward marriage and commitment.

Steve and Janet endure various calamities on their honeymoon. Just as they are beginning to have a good time, Janet goes into labor. Although the birth is expected to be routine, the doctors are forced to perform an emergency C-section. Janet and the baby experience life-threatening complications. Jackie seeks full custody of Erin, and David and Kelly try to keep their sister's spirits up. Jackie tells Kelly that Gina blackmailed Mel. David refuses to believe this, and Gina denies the allegations. He learns the truth from his father, but decides to give Gina another chance. Dylan helps Andrew get his job back and fights the prejudice at the community center. Kelly complains about Noah's monopolization of the apartment. Donna buys genealogy software as a wedding gift for Steve and Janet. She accesses Gina's birth certificate and discovers that Donna's dad is listed as the father.

The Martins ask Gina to join them for Christmas. However, they refuse to allow her at their Christmas Eve party because they don't want to explain the situation to friends. Donna initially backs her parents, but skips the party to show Gina her support. Donna continually questions Noah about the car accident that killed his girlfriend. Noah finally breaks up with her, as he cannot bear to relive the tragedy. Felice is clueless as usual when she assumes Gina wants money and offers her a blank check, so Gina tells her to go to hell, but Dr. Martin later comes to Gina and apologizes for what was done to her. Steve and Janet run into her parents at a tree lot. Janet invites them to dinner, where they behave coldly toward Steve and make a hasty exit. Steve tells the Sosnas they're invited over for Christmas but "just know it's your last chance" to embrace the entire family. They show up at the house on Christmas night and give Steve and Janet their blessing. Dylan proves to be a bad influence on the children at the community center after he punches an angry neighbor. Matt asks Kelly to marry him. Dylan also expresses a desire to commit to her. Kelly doesn't choose herself this time; she accepts Matt's proposal.

Matt gets into hot water after a client decides to settle; he had already spent the man's retainer on Kelly's engagement ring. Gina tries to help by asking Dylan for $15,000, without telling him who would receive it. Matt turns down the money and has to pawn Kelly's ring. He is suspended from practicing law for 30 days, leaving his practice on the verge of bankruptcy. Dylan acts very aloof around Kelly, and loses interest in his god parenting duties because he doesn't want to spend time with her. A bitter Gina denounces the idea of god parenting, because Dr. Martin had served as her godfather as a means of easing his guilt. She changes her mind and tells Dylan that he could be a positive influence on Madeline. He shows up at Madeline's baptism at the last minute and impresses everyone with his speech. Donna has a disastrous date with the guy who runs the coffee stand next to her store. Noah spends all his time partying with a bunch of weird people. As he moves out, he and Donna act as though they long to get back together for the umpteenth time.

Matt violates his suspension by negotiating a settlement for a worker injured on the job, who would lose his right to file a complaint in two days. Matt sets up David on a date with an attorney friend who is on the ethics committee. David blabs about the case, and the woman warns Matt to cease his involvement or be reported to the bar association. Matt just laughs it off and continues his work, so Chrissy reports him. Matt's suspension is doubled, and David stops seeing Chrissy because he considers her a traitor. Kelly announces that she is quitting the store. Donna gets a date with a handsome man who turns out to be married. She and David decide to hang out together in their own "losers' club." Gina receives a spokesmodel offer after she and Dylan are pictured at a hot club in the society pages. Noah and his entourage leech off of Dylan and his money. Dylan objects when they do drugs in his limousine. Dylan and Gina get pulled over for speeding in the limo. The police find cocaine in the back seat and arrest them. Despite her innocence, Gina loses a chance at the job. Dylan clears them by identifying Noah's friend (and Dylan's one-night stand) Josie as a drug dealer. Josie flushes her supply, but her junkie brother threatens Dylan. Steve and Janet hire a perky young nanny. Noah takes her out and discovers that she is a nymphomaniac. Steve realizes that he slept with her during college.

Shane demands a one-million-dollar ransom from Dylan. Noah points out that it may have been smarter to kidnap someone whom Dylan actually likes. Dylan agrees to pay the ransom; but Shane kidnaps him with help from Josie, who had claimed to be unaware of her brother's whereabouts. Shane plans to kill Dylan and Noah because it couldn't get him into any more trouble than he already is. They escape while the kidnappers are filling up their van, and scuffle with Shane and his friend. Josie hands over her gun to Dylan because she doesn't want anyone to be murdered. She drops a lit cigarette, which ignites the overflowing gasoline. Although Dylan tells him to forget it, Noah retrieves the ransom money before the van explodes. The kidnappers get arrested. Dr. Martin invites Gina to dinner while Felice is out of town. Gina tries to bond with him, but is angry because he had not called her since Christmas. Dr. Martin visits Gina's hotel room and expresses a willingness to work things out. They embrace, and she agrees to call him "Dad." Gina trains her father in an effort to get him into shape. As Donna arrives for the trio's dinner engagement, Gina finds that Dr. Martin has collapsed. Donna tries desperately to revive him. Kelly becomes ill just before she is to appear on a couples game show with Matt, so Donna takes her place. Matt comes to believe that Kelly shares too many details of their private life. David fears that Camille is going back to her rich ex-boyfriend.

Dr. Martin dies of a stroke. Kelly suggests that Gina is to blame for his death, as does the grief-stricken Felice. David also seems to support this theory and makes sure to be as unsupportive of Gina as possible. Gina is upset when the obituary states that Dr. Martin has only one child; Felice calls her a mistake. Donna feels that Dr. Martin would still be alive if Gina hadn't discovered he was her father, even though Donna was the one who shared this information. Dylan, who was the only person to defend Gina during this ordeal grows tired of Kelly's whining and moralizing. He and Gina decide to leave town. Gina is not allowed to sit with immediate family at the funeral. However, she goes to the front of the church and finishes the eulogy when Donna is unable to continue. Felice embraces her and accepts her as part of the family. Dylan decides that he shouldn't leave Los Angeles because he has unfinished business with Kelly, something that Gina is neither surprised or that upset by. Gina says goodbye to Donna and embarks on a cross-country road trip. David comforts Donna throughout her ordeal. Kelly takes a public relations job to ease the financial burden created by Matt's suspension. She is shocked to learn that she must campaign against gay students' right to form high school clubs. In the aftermath of the kidnapping, Noah becomes depressed and drinks a lot.

Kelly grows suspicious of Matt's distant behavior. She seeks answers from Dylan, who denies that anything unusual happened during their dirt biking weekend. Matt admits to drinking spiked punch. After witnessing Kelly's indignant reaction, he decides not to tell her about his one-night stand. Kelly insists that Matt is still hiding something from her. She later apologizes for failing to trust him. Camille tries to convince Donna to sell her clothing online. Although Donna doesn't support the idea, Camille seeks out Dylan as an investor. Even after Donna agrees to the proposal, David fumes at Camille for going behind her back. He also expresses discontent at the amount of time she is spending with Dylan. Donna agrees to a date with the web page designer. Steve and Janet fear that her parents' dog is to blame for the death of their snooty neighbors' pet rabbit. Steve concocts a scheme to keep the couple from discovering the truth. Ellen objects to Noah's efforts to help her establish a normal life. Donna reminds Noah that he cannot single-handedly save Ellen.

While preparing for her and David's wedding, Donna asks Nat to give her away at the wedding, since she always saw him as a second father. Steve and Janet start their own newspaper company after selling the Beverly Beat. Andrea and Valerie return for Donna's Bachelorette party and gives the girls and the guys videos of Brandon congratulating the bride and groom since he couldn't be there for the wedding. The wedding goes off without a hitch, and Matt shows up to make peace with Kelly, and tells her she should be with Dylan and he leaves for New York. Noah decides to committ to Ellen and leaves the wedding and Kelly and Dylan get back together. Then everyone starts dancing and the gang gives each other one final group hug and the series ends.