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.""

Samuel and David are home and won't stop crying. Matt gets a new job at the Dairy Shack as a delivery guy. Mary sneaks to the pool hall to meet Wilson while Lucy covers for her at home. Lucy ends up doing all the cleaning by herself. Mary hangs out with Jordan as Wilson arrives. Wilson is thinking of moving back to Glen Oak, but Mary realizes she doesn't have feelings for him anymore. Ruthie wants to run away from home because she doesn't get much attention as she used to. Annie gives Ruthie her baby book. Simon orders food from the Dairy Shack to check out Matt's new job. Matt is fired from his job and meets an old girlfriend, Shana.

Eric suspects Lucy's ex-boyfriend Jimmy Moon is involved with drugs. Eric and Annie and the rest of the Camden family forbid Lucy to neither see nor speak to him anymore. Lucy does not listen to them and she gets a lot more than what she bargained for when trying to help Jimmy. Meanwhile, Ruthie tries to keep Matt and his new girlfriend Shana apart as she avoids telling Matt that Shana has been calling the house. Lastly, Simon tries out for the baseball team and uses Mary as a good reference, even though he stinks.

Moral outrage explodes in the community over an affair between a college president and a student at Matt's college. Simon and Ruthie go on a paper route, but some problems occur when Mr. Mallone does not want to pay the paper fee. Mrs. Hinkle tries to help Simon and Ruthie in their situation. Matt gets into a fight with some people at his school due to a disagreement of opinions with the chancellor's affair. Mary convinces Lucy to go on a date with the guy Mary SUPPOSEDLY smashed her car into.

Eric defends a custodian named Rudy from Simon's school who claims to be hearing messages from God and is forced into early retirement through the school board. Annie wants to cut loose for the evening, and does so with other fellow mothers. Ruthie encounters a chimp living in the Camden's tree in the backyard, but nobody in her family believes her when she tells them about it. Mary stays up babysitting for the twins when the parent's are out, and is ditched by Lucy.

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.

Eric develops a child-like fascination with life when he takes a much-needed vacation after his heart attack episode, while Annie runs into interference with each of the kids. Meanwhile, Simon assumes the role of the 'man of the house', but feels Matt is undermining his authority when he keeps on making fun of him. Also, Matt grows uncomfortable with the blossoming friendship between his girlfriend Shana and his roommate John Hamilton while he's busy with other issues. Also, Lucy finds a direction in her life with her interest in Habitat for Humanity after taking her fathers advice.

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.

Mary and her friend Corey Conway learn that they have been named recipients of their senior classes ""All Sports Award"" and they are both thrilled. Although, the local businessmen revoke the honor from Corey when they learn Corey is a mother. Angered and hurt by their actions, Mary gives her reward to Corey in front of the entire assembly. On the home front, tensions build after Eric and Annie find a bag of marijuana in Simon's new friend's backpack. They confront his family (who at first deny there is an issue), but after a successful intervention with the police, the boy's father agrees to seek counseling and to find a job. Meanwhile, Matt faces a disciplinary action after he breaks the honor code during a school exam. Also, Lucy questions herself whether she should help a boy she likes to access the school's computer system when she's working in the attendance office.

Mary and her basketball teammates are upset when their high school coach imposes a lockout on the season, citing that their studies should be top priority. When the school calls a meeting to discuss the situation, Eric and Annie support the coach's concerns and decisions. Outraged by the apparent betrayal, Mary and some members of the team break into the gym and vandalize it. They are soon caught by the police and are arrested. Meanwhile, sparks fly when Simon is caught making a lewd hand gesture in front of the school, and is busted. Also, Matt contemplates returning home and Ruthie obsesses about being one of the guys.

The Camden family rallies together after Mary's arrest. Mary truly learns the consequences of her actions after she learns that she is losing her scholarship to college, faces possible school expulsion and jail time. Eric and Annie enlist the help of a lawyer who manages to get Mary enrolled in a community service program. Simon and Ruthie feel overwhelming pangs of guilt for having some knowlege of Mary's intentions and not telling their parients about it. Simon and Ruthie decide to visit many different houses of worship to attain atonement. Also, Matt moves back home to help with the family, but soon realizes he needs to live on his own.

After Eric receives a mysterious check of $20,000, he learns that the gift was from one of his parishioners who was a World War 2 internment camp survivor. When he hears that the woman has never been able cope from her internment experience, Eric helps her come to terms with the pain. Meanwhile, Ruthie learns a valuable lesson about the meaning of friendship when bribing a classmate. Matt and Shana have a miscommunication about laundry that sends their relationship temporarily into a tailspin. Simon is woeful over the injustices of the world, and Mary adjusts to her lower social status at school.

In order to get extra credit, Simon volunteers to paint a holiday mural with a few good guys in his school. The other volunteers don't like Simon because they are inhaling paint fumes and are afraid he will report them. When one of the boys winds up in the hospital, Simon is accused of providing the paint. After he confronts the boy, the boy decides to confess everything to his parents. Meanwhile, Mary is suddenly thrilled about her community service after she meets the man of her dreams: Robbie Palmer. Eric and Annie are hesitant to allow Mary to pursue a relationship because of her punishment, but do allow Robbie to call her. Matt is up in arms when he learns that Shana is transferring to NYU and that his father provided a reference without his knowledge, and Ruthie wins first prize in her art-school project: a sculpture of the Camden family noses.

When Ginger pays the Camden family a visit, she informs Eric and Annie that her father is in the early stages of Alzheimer's Disease. At first, Annie can't believe it, but after observing him in the backyard and not paying attention to a fire in the barbecue, Annie realizes the truth. Meanwhile, Mary and Eric can't see eye-to-eye on her relationship with Robbie, but they soon agree to compromise. When Mary informs Robbie of the plan, he tells her that it won't work between them. Fortunately for Mary, Robbie changes his mind after talking to Eric in the local grocery market. Also, Lucy gets into trouble after blowing off a Habitat for Humanity project to go on a date, and is caught. Meanwhile, Matt is consumed with depression due to Shana's upcoming move to New York. By this, Matt pays no attention to Simon, who just wants to spend time with his big brother. Also, Ruthie makes a vast millenium preparations until Eric provides her with a more grounded perspective.

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.

Eric and Annie reluctantly allow Mary to go out with Robbie, on the condition that they double date with his younger brother Rick (guest-star, Lance Bass, ""N'SYNC"") with Lucy. Meanwhile, Simon and Nigel buy several packs of cigarettes for a class project to prove how easy it is for children to buy tobacco. Also, Ruthie works out her own secretive science project and John invites some female neighbors over for dinner to take Matt's mind off of Shana.

Reverend Camden helps a new family in the congregation who has a son suffering from Tourette's Syndrome. With the assistance of Simon, Simon sticks up for the boy at school when bullies pick on him. Meanwhile, Annie takes matters into her own hands when she horrifyingly learns from Lucy that Ruthie's teacher has reportedly been calling her ""stupid."" Simon unknowingly hurts Mary's feelings with something he said to her earlier, and Matt puts his girlfriend Shana on the silent treatment when he contemplates calling things off.

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 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.

St. Valentine's Day delivers a few surprises for the Camden family. A grounded Simon is asked out by a senior. Annie's attempt to surprise Eric with romantic Valentine's plans backfires and results in a big fight. Mary discovers Robbie's plans with Joy. Lucy and Mary learn that Jeremy and Wilson both have dates for Valentine's. Matt seeks his fathers help as he wants to settle down, which leads him to seek out old girlfriends as to why they're no longer together. Ruthie is hesitant to go to a party because her friend tricked her into asking out a boy she's already going out with.