Annie and the girls are fixing up an old car for Matt as his college present for him as he moves into a fraternity house. Simon is having a hard time living around the girls when fixing up the old car and needs to be around some male energy, especially after hearing from his mom that two more girls MAYBE on the way when she predicts the twins' sex. Meanwhile, a new woman at the church flirts with Eric. Lastly, Matt's friend almost dies after drinking too much for an initiation at a fraternity party and Matt quickly takes him to the hospital.

Lucy is spending a lot of time with her new best friend, Nicole. They are both in the same biology class, and are both failing. Eric offers to tutor both of them. Matt is upset because a girl rejected him. He later learns she did that because she already has a boyfriend. Ruthie fails her math test on purpose so she can get more attention from her mother. Simon wants her to stop, and tells her he'll pay 50 cents for every good answer she gets on her next test. Ruthie gets all the answers right, so Simon has to pay her $20. Mary catches Nicole cutting herself in the bathroom. Mary tells Eric, who then tells Nicole's father. Eric gives him a card and a number to call so they can get help for Nicole. Nicole and her parent's are moving to Chicago for a couple of months, so she can follow therapy.

Simon sees his teacher push a man who was screaming at his son. He then feels guilty when he learns his teacher got fired. Annie takes piano lessons as her ""pregnancy project."" Meanwhile, Matt makes a move on one of his college teachers. It turns out he misunderstood her signals. Mary and her friends skip a boring class and get caught. Also, Lucy forgets her lunch in geometry class and finds her teacher eating it--- two days in a row. She and her friend Shelby then learn a good geometry lesson. Lastly, Ruthie has trouble finding the perfect instrument for music class.

Eric is trying to cheer up a woman whose son died three years ago. She wants to meet the people who received her son's organs after he died. Mary got her driver's permit, but not everyone is enthusiastic to ride with her. Meanwhile, Lucy and Simon decide to take the bus. A freshman has a crush on Lucy and sits beside her, which makes his girlfriend jealous and angry with Lucy. Simon gets into some trouble with this tough guy who wants help with his homework. Also, a pregnant girl steals Matt's car and leaves Matt with her broken car, which happens to be stolen. She is running away from home because her parent's don't forgive her for getting pregnant.

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.""

Eric and Annie are taking prenatal classes--- for the sixth time. Annie helps two teenage girls get through their pregnancy while Eric helps the two teenage fathers deal with the news and finding a job. Simon is taking babysitting classes and gets his first job babysitting Ruthie, although it doesn't go quite the way he expected it to. Meanwhile, Mary is sneaking to a coed basketball sleep over. Plus, Lucy is thinking of having sex with Jordan to see if he's really attracted to her, but it blows in her face. Lastly, Matt has to do research on sex for his class and is having trouble over finding a topic..

It's the Christmas season and Eric has his three oldest children doing charity work for the community. Mary and Lucy aren't enthusiastic about the charity work that Eric wants them to do. Mary is working in a soup kitchen while Lucy has to organize auditions for the ""Live Nativity"" at the church. Meanwhile, Eric has given Matt a well-paid job as Santa Claus at the mall. Also, Simon is in the spirit of wearing his VERY tight candy cane pajamas and wanting to put on lights inside the house since he's not allowed to do it outside alone. As a family ritual, each family member picks a name out of a hat of who to get for Christmas while Eric and Annie cheat. Before going on his family vacation, Jordan accidently gives Lucy a gift that was meant for his uncle's monkey (shoe shine-kit), but was supposed to give her a basketball signed 'I Love You'. Also, Mary meets a a guy, Carlos at the soup kitchen who doesn't have a place to stay for Christmas, so Mary invites him to stay over at their hous

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.

Lucy is spending the weekend at camp 'All By Myself'. It turns out everyone at the camp has to spend the weekend all by themselves without talking to anyone. Ruthie is angry with classmate Bobby Tripp because he keeps making fun of her since he accidently saw her underwear. Now, Ruthie decides to make him realize what he did was wrong by starting a war: Camdens vs. Tripps. The church's women group throws a baby shower for Annie. Eric and Matt have lunch with Morgan and John Hamilton. The manager of the restaurant doesn't serve Morgan and John their meal because he doesn't serve black people.

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.

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.

Simon persuades his parents to let him go to a party after they meet his friend, a senior who promises to look out after him. When he comes back home completely drunk, he puts his siblings in a terrible position on what do. Matt gets letters from two medical schools but he is hesitant to open them and they eventually end up with Ruthie. When Mary and Lucy take the same classes at an area college, they decide to go to a bar with Lucy's friends.

A startled Eric catches Mary and Lucy in the kitchen with Ben and Kevin in the middle of the night. The guys end up spending the night in the living room with Mary ad Lucy. Ben and Kevin's sister calls the house to inform Ben and Kevin that their mom is going out with a neighbor. Eric suspects that Ruthie knows a secret about Matt and Sarah and thinks they are married already. Meanwhile, an older couple seeks guidance from Eric when they can't seem to let go of their forty-four-year-old son, who has run away from home.

Matt and Sarah grieve over Eric's decision not to attend the nuptials following his argument with Rabbi Glass over Matt's conversion to Judaism. Hoping to patch things up between their fathers, Matt and Sarah seek their mothers' help in persuading them to put aside their differences before it's too late. Ben and Kevin come to Glenoak to meet up with Mary and Lucy so that they can resolve their problems. Robbie tries to figure out why Ruthie wants him to move out of the Camden household.

Against Eric's wishes, Simon asks Mrs. Kerjesz (guest-star real life survivor, Rita Zoharm) to tell her story about being in the Holocaust in his class presentation. To form a strong sisterly bond, Mary and Lucy decide to hate Matt's new girlfriend for no good reason and end up hurting her feelings and breaking up with Matt. Also, Annie suffers heartache when Ruthie tells her she ""hates"" her for making her clean the walls in her room after scribbling crayons on them.

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.

Ruthie is nervous when she finds out that Eric and Annie are heading to Scotland. She reveals a very unattractive side of herself when she openly admits that she's not about to sacrifice her own freedom and happiness to come home and be with her sick father. Kevin has a difficult time helping Lucy come to grips with Eric's illness; Sandy accepts Martin's marriage proposal just to get rid of her clingy boyfriend; and Kevin finds out a secret about Jane.

Mary tries to make Wilson say that he ""loves"" her, but Wilson thinks it's a big commitment and that they haven't known each other long enough to say those words to each other. Meanwhile, Simon and Ruthie are reading Matt's love letters to Heather and get caught. Matt tricks them by addressing one of the letters to ""Mrs. Matt Camden."" By this, Eric accidently finds the letter leading to think Matt and Heather got married over the summer, which worries himself, Annie and Heather's mom, Mrs. Cain. Lastly, Eric helps Lucy's friend, Laurie get closer to her mother.