Annie's father, Charles is getting married to his girlfriend Ginger. The wedding reception is supposed to be at the Camden's house and Annie is the one in charge of preparing the menu. Annie isn't enthusiastic about the wedding and the reception. On her way to the grocery store, she meets a homeless veteran and invites him home. He is the one ending up preparing the menu since he was a chef for forty years. Also, Matt and Mary are taking a little road trip, which ends up being very long when they get a flat tire. Simon is spending the day with his new girlfriend Deena. Lucy is spending the day with Jordan, the guy she can now call her boyfriend. Lastly, Ruthie is feeling lonely, so she pretends her imaginary friend Huey is back the whole day.

Ruthie wants the ""Booboom"" video game that her friend has and is walking around the house pretending she is dropping bombs which is annoying Annie a lot. Simon has a BIG problem at school when his girlfriend Deena tells him that her former boyfriend Johnny just got dumped by his girlfriend and might be coming after him so he could get back together with Deena. Johnny then threatens to shoot Simon the next day at school. Simon tells Eric this and tries his best to settle this matter leading to bad consequences on both sides as someone gets shot. Meanwhile, Matt introduces Mary to his friend Shana and her brother. He asks Mary out on a date, but has no idea that he has a BIG problem--- he is violent. Meanwhile, Lucy tries to be romantic with Jordan and wants to slap him after watching ""Gone with the Wind.""

Mary gets her driver's license, but can't parallel park. She cried during the test because she couldn't park, so the teacher passes her anyway. Meanwhile, Simon learns that his girlfriend Deena had leukemia when she was five years old, but went away. Although, every year she has to go for a check-up to make sure the disease didn't come back which worries the both of them. Also, Ruthie calls a woman who she thinks is a psychic and asks her if Deena is going to be all right. Lastly, Eric's sister, Julie is back in Glen Oak and she has a new job and is starting a life of her own now. Eric and Matt want to help her get settled in Glen Oak, but are trying to help a little too much.

Simon wants to buy the perfect gift for Deena because its their three month anniversary, but it ends up consuming his time which annoys his friend, Nigel, who's visiting. Rod (Lucy's ex-boyfriend) is spending time at the Camden's home because his mother died and doesn't want to face his father as he's angry with him. Heather is back in town, and she tells Matt that she's engaged. Meanwhile, Dr. Hasting's---the doctor who almost killed Matt when he was born, works at Glen Oak Hospital and Annie is not thrilled, especially with the possibility that he may deliver her twin babies. Mary tells everyone that she's back with Wilson, but it's not true. She made it up to get attention from guys. Lastly, Michael Towner, who hitted Mary with his car two years ago calls her.

Two parishioners entreat Eric to take their suffering dog to the vet to be put down. Matt catches Mary in a lip-lock with Michael Towner in a most unlikely place. When caught, Mary gets into a big fight with Matt because he's always intruding in her life. After a night of cooling off and a talk with Sgt. Michael's and each other (Matt and Mary), things go back to normal. Simon and Lucy double date together with birthday girl Deena and her older brother who is visiting. The dates are a success.

Eric worries about Matt as Heather's wedding approaches. Eric learns that his sister Julie is dating Dr. Hastings (the doctor who delivered the twins and almost killed Matt at birth) without telling him or the family. Also, Lucy and Simon are both in their awkward love triangle between all of their two best friends and lovers. Ruthie wants to be a bridesmaid and a bride at Heather's wedding.

In the third season finale, Eric counsels an engaged couple facing difficulties. Mary, Lucy and Simon learn the repercussions of forbidden love, especially Simon when he is caught in his bedroom alone with Deena kissing near his bed. Julie gets married to Dr. Hastings (Hank) and learns that she's pregnant. Also, Heather breaks up with her fiance after she learns he was cheating on her with another woman. Matt tries to save his relationship with Shana after he ran off with Heather, and does this through his pleading of forgiveness.

Each of the Camden's are learning a lesson in equality as Annie and Lucy join together to protest the mistreatment of women in Afghanistan. Eric counsels a young couple about the importance of sexual equality in a marriage. Simon considers dropping out of a cooking class he enjoys because he is the only boy enrolled. Also, Mary helps Ruthie with her secret plans to defy convention and play on the school football team. Meanwhile, Shana confronts her long-lost father who abandoned her family 20 years ago.

With Annie and Lucy adding a new bathroom, and the need for a new car, Eric is depending on his built-in annual raise from the church board. However, when the church deacons gets the wrong impression about the Camden's financial situation, they reject his annual raise. It's up to Ruthie to save the day when she realizes what is going on and to convince them to change their minds about their plan. Meanwhile, a young hospital patient (Josh Evans, ""Passions"") offers Matt some career advice. Also, Simon attempts to entertain a classmate who has a crush on him.

Eric and Annie put on their counseling hats when a very pregnant Julie appears on their doorstep prepared to leave her new husband Hank. Eric decides to take Hank out to dinner to discuss their issues. While they are at dinner, a very pregnant Julie goes into early labor. Unable to transport her to the hospital because Simon and Mary are out to dinner and Lucy is on a date, Annie does her best to calm Julie down. Hank and Eric return to the house just in time for the birth. Julie delivers a baby girl. Grateful for Eric's effort, Julie names the baby after him: Erica. Meanwhile, Lucy is disappointed when her date expects her to be 'the man', and Simon attracts the attention of an older female admirer.

Annie decides to take a much-needed break from the family and heads to the beach on a solo trip to get some rest, leaving Eric (Mr. Mom) in charge of the large household. Meanwhile, Matt must relunctantly say goodbye to Shana as she leaves for NYU. Mary impatiently waits for Robbie to call her. Also, Lucy realizes that she may be interested in the wrong guy, and Simon learns some tips from his sisters on how to treat a girl.

It's Valentine's Day and the Camden's are celebrating the day of love with a special party in honor of the twins first birthday. Eric and Annie fret over how to make the babies birthday a memorable one, while the rest of the family learn different ways of exchanging love on Cupid's Day. After finally gaining her parent's trust, Mary is allowed to spend a romantic dinner with Robbie, only to learn he has ulterior motives. Meanwhile, Simon and Deena confess to their parent's that they've given each other love bites. Also, Matt welcomes his ex-girlfriend Heather back into his life, threatening his relationship with Shana.

Eric Camden finds himself on a hung jury of a case that he considers ""open and shut,"" only to realize that he must help the other jurors regain their faith in the legal process in order to reach a fair verdict. Meanwhile, the other Camden's are suffering their own wrong doings as Annie and Ruthie ponder whether two wrongs make a right. Mary becomes in debt with Lucy after accidently giving her a black eye. Also, Simon and Deena realize that saying ""sorry"" can't turn back time, and Matt learns how important one person's voice can be.

Eric and Annie must deal with the emotional fallout as they learn about their kids tumultuous love lives. Mary upsets her parents by announcing that not only has she decided to skip college in the fall, but she is getting back together with Robbie. Matt is forced to choose between his girlfriend Shana (who has moved back to Glenoak for the summer) or his ex-flame Heather, who confesses that she still loves him. Lucy dates Robbie's cute brother Ronald, disappointing Andrew Nayloss who still harbors feelings for her. Also, Simon gets dumped by Deena and Ruthie takes advantage of her new boyfriend.

In the fourth season finale, Simon finds out the real reason why Deena wants to break up with him. Also Ruthie does her best to get back together with her old boyfriend Burt, while Lucy also tries to go after an old flame: Andrew Nayloss. Mary decides to take things slow with her relationship with Robbie and her life. Matt and Shana break up their relationship, but reconciles with Heather. At the end of the show, it shows Matt and Heather may have gotten married- but didn't.

Mary's feelings for Robbie resurface when she inadvertently finds out he has a secret date for Valentine's Day, and the whole family schemes to uncover the mystery woman. Meanwhile, with the exception of Lucy who has a date with Jeremy, the other Camden kids feel deflated when their Valentine's plans fall through and they end up stuck at home celebrating Sam and David's second birthday. Lucy and Jeremy's first date does not go as expected as they both keep on running into Lucy's ex-boyfriends. Although all's well that ends well by the end of the episode for everyone.

Mary returns home back to Glenoak for the summer to spend some time with her family, but fears about being together again with Robbie. Eric and Annie are recipients of what may or may not be advances from unmarried acquaintances. Simon and Deena see that they still have feelings for each other, even though she has a boyfriend. Matt agonizes over telling his family about his new relationship with Cheryl, but soon decides to tell them all. Lastly, Lucy surprises herself and others when making a proposal to Jeremy and the possibility of going to college in New York with Jeremy. Although plans change when Mary, feeling rejected by Robbie, makes a shocking declaration.

Mary tries to right a wrong by explaining to Lucy that she never had adult relations with her sister's fiance. The only problem left is trying to convince Lucy. Wilson unexpectedly drops by the Camden home from New York to see if he and Mary are really over by finding out her answer. James talks to Eric about him attempting to have an affair with Annie as Serena comes clean with Annie about her trying to have an affair with Eric. Robbie and Wilson set aside their differences so that they can talk about Mary. Matt learns a few things when it comes to Cheryl's honesty when she doesn't tell her friends that she's dating him.