As Mary faces surgery and a long recovery, she and her family must face the reality that her basketball career might be over. Meanwhile, Annie has only one option left if she wants to maintain her relationship with her father. Matt drives Heather even further away when he gets into an ugly confrontation with a classmate. Lucy gradually recognizes the truth about Jimmy's feelings for her. Wilson is eager to start dating Mary, but there are a few important details he must share with her father first.

Annie is thrilled that her father is coming to visit for the first time since her mother's death, but she is furious when he shows up with a new girlfriend. Elsewhere, Simon convinces Lucy that she would look good with a blonde rinse, but is prepared to run for his life when it does not come out as good as Lucy thought it would. Mary meets a handsome young man who is harboring a few secrets, and Matt becomes attracted to a girl who is deaf. Lastly, a potential tragedy in the family puts everyone's trivial problems into perspective.

Matt is uneasy when his mother's oldest friend—a boy crazy divorcee named Rachel, makes a pass at him. Mary goes with Matt and Rachel to a coffeehouse, and makes her public singing debut when she learns the band's singer didn't show up. When Mary gets a phone call asking her to fill in again, Eric and Annie are shocked by the news, but they agree with one specific condition: they are going with her. Back at home, Ruthie has a going-away party for her longtime imaginary friend, Hooey, and Lucy tries to cope with the fact that her best friend, Suzanne, is moving away.

Eric's difficult-to-please parents arrive with their newly adopted young son in tow. Everyone is pleased to discover that the Colonel and Ruth seem positively different since taking in a new child, but things get messy when George's biological father shows up with a desire to be part of the boy's life. Meanwhile, Julie is out of rehab and terrified to reconnect with her family, and with a little help from Matt and Mary, Lucy prepares her boyfriend to meet their formidable grandparents.

Eric wants to hire an ex-convict to be the new organist, but the church vestry think that the money in the budget would be better used to put up a security system. Acting church treasurer, Annie must determine whether there is enough money in the church's budget to hire a new organist. Meanwhile, Lucy's imagination runs wild after she makes Mary tutor her boyfriend, Jimmy Moon. Simon tries to get Matt to let him out of getting a tetanus shot that he needs for his upcoming little league season. Lastly, Ruthie feels empowered by her new class phone list and decides to test the emergency phone numbers.

Mary pays a rare visit to detention and meets Camille—a wild, free-spirited girl who loves to break all the rules. Against Mary's better judgment, the girls become friends, and Camille talks her into making a foolish decision. Back at home, Eric and Annie counsel a man who used to work with Eric and is harboring a painful secret. Lucy confuses her father with a desire to research other religions, while Simon and Ruthie run into trouble at the pet store.

Lucy asks Eric to investigate her new best friend's white lies as to where she and her family really live and their financial situation. Matt intervenes when a bully harasses Mary at school. Simon is jealous of Ruthie's new friend from her pre-k class as she's more fascinated with him now than Simon. Lastly, Ruthie's first day at school brings melancholy feelings for Annie.

While both couples, Annie and Eric, Patricia and Morgan Hamilton, spend a romantic Valentine's Day camping, Matt is left in charge of the rest of the family and allows chaos to rein in the Camden household. His preoccupation with his date and Mary's party allows the dog, Happy. to slip out of the house in search of her puppies. When a car hits Happy, the family holds a vigil, aided by a caring veterinarian. Simon blames Matt for the accident. Lucy is enjoying her first Valentine's Day with her boyfriend Jimmy Moon.

All three Camden generations dread the annual visit of Eric's parents, "The Colonel" and Grandma Ruth Camden. The tension between father and son is heightened when both Eric and "The Colonel" want to adopt a homeless and orphaned nine-year-old boy, George. Annie discovers the fate of her lost wedding rings when seeing them on a woman at the store.

Matt takes the blame for something Mary did, complicating the rift between Matt and Eric; Lucy takes credit for a paper Mary wrote.

Eric tries to help a homeless family; Matt helps old Mrs. Bink around the house; Lucy is depressed about her birthday; Happy has puppies.

The Camdens become suspicious when Matt's new girlfriend, Tia, wants to spend more time with the family rather than being alone with Matt. Lucy enlists the help of Matt to overcome her clumsiness in order to try out for the cheerleading squad. Annie yearns for more romance in her marriage with Eric as she has become bored with the every-day routines. Simon tries to make himself invisible and tries to convince the whole family that he can be invisible.

The Camden family's traditional Thanksgiving is jeopardized when the children want to spend the holiday away from home and Eric's sister reveals a tragic secret.

Simon rightly fears he'll catch roommate Ruthie's chicken-pox, but his enterprising hygienic measures fail to prevent contagion from her or happy's flees. When a robber carjacks them both, Annie seems calm and hands their valuables, so Matt feels 'unmanly' and guilty. However when it comes to an identification line-up, Annie breaks down, only sneakily. Jimmy Moon stands against Lucy in the school elections, then turns to her parents for help. The organist has bizarre periods of excellence and disharmony.

The family suspects the worst upon seeing Eric and Abby Morris at a motel; Simon has a crush on a classmate.

Mary does not want the family to come to her big basketball game; the Camdens are in a frenzy when Ruthie and Simon are lost.

Despite warnings from her family, Lucy tries to learn the truth about Mike "The Mutant" Mitchell, a mysterious recluse accused of murder.

When the Camden family learns that their friend's church was burned down by a racist group, they invite the Hamiltons to stay at their home. Meanwhile, Simon has his own problems when defending his friend Nigel after a racist comment is made to him on the playground. Matt, Mary, and Lucy have a hard time while trying to develop a good relationship with the older Hamilton children, Keesha and John. Eric and Annie do their best to help Morgan and his wife, Patricia, get through their marital problems while Ruthie and Lynn are having fun as five-year-olds.

Following her mother's funeral, Annie's sunny demeanor turns to sadness, particularly after her father abruptly leaves to go back home to Arizona. Eric tries to counsel a young couple whose marital problems escalate during the post-funeral reception at the Camden home. Matt helps with the delivery of Renee's baby and after Mary breaks up with Jeff, she discovers she was better off with him. Lastly, Simon tries to find the exact location of heaven.

Matt, Mary and Lucy learn the art of dating; Annie's parents move into the Camden home.

When Eric and Annie discover that Matt has a secret girlfriend named Renee, they are shocked to see that she's pregnant; with Matt insisting he's not the father. Both Matt and Renee are surprised at Eric's willingness to help her out once she delivers. Mary discovers Lucy has a crush on a classmate and makes fun of her for it. Eric starts losing his shoes and turns to Ruthie for help in finding them. Annie confides in Matt that her mother is sick with leukemia.

Eric tries to stop 16-year-old Matt from smoking; Eric and Annie field Simon's nonstop requests for a pet dog; Mary asks Matt for advice about kissing boys.