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.

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.

Mary tries to impress her basketball team by stealing a glass from their teen hangout "The Varsity", which is a school ritual. A misunderstanding occurs which winds up with Matt being arrested for stealing the glass. Lucy cheats on a school paper by taking one of Mary's old papers and putting her name on it. Ruthie asks Simon about help when she overhears her father talking about how it bothers him when people in America don't know the National Anthem.

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.

The reverends get their spouses to handle the annual two-families-day so they can go play pool. In fact Morgan arranges finally to meet his wife's ex Kevin, who turns out to be a happily remarried Vietnam vet in a wheelchair. As Eric expected, all kids want to do things without any parents, so only the youngest are dragged to a cartoon movie by the moms. Simon is excited about his first 'making out' party, yet terrified when it's time to step into the closet and probably kiss. Scott is 14 but looks 18 and tutors Lucy maths just so he can successfully treat Mary to a date, only to be kept on a string. Matt is surprised that the jazz club John dragged him to is his mate's singer career bid launchpad, unamused to be asked as support against Morgan. Lucy has her own date Rick, but chose the same cinema as Annie.

With the twins birth impending, Eric makes the kids' life miserable by fussing and over-planning, yet blames Matt for preparing the youngsters for what's ahead. Annie adds to the mess by inviting over the Hamiltons, just so Patricia can help her ward off the parish busybodies, who forced a baby-shower on her so they can snoop around the church-owned home. Ruthie acts as if a victim when classmate Bobby points out her underwear visible by failing to wear school-regulation shorts. Her elder siblings are pushed to confront Boby's family, but his brothers aren't only taller, like their dog, they also bond with Matt and Mary and end up turning on the brats together.

The monthly day when the twins' piggybacks are enriched with §10 is ahead, so the siblings fear the game is up unless Mary manages to repay the 'loan', but now her debt is reshuffled she idly spends her days in the movie theatre. So the Camden parents soon learn the dreadful truth they already dreaded. After pondering how to help her, a family intervention proving she's still in haughty denial, the last resort is packing her off to Buffalo, to be taken in hand by the Colonel.

Only Robbie refuses to sign, Eric alone not being eligible, Ruthie's petition against a popular ethics teacher Miller's rumored prejudiced dismissal. Robbie learns about the household rule you can't complain over 18 about anything vaguely political without registering as a voter. Matt is first to work out the televised petition commotion is an unsavory misunderstanding, for which the school kids are tricked into fake detention by her brother. Annie's pa recently found out and now wants her and the family to know she has an older but illegitimate sister, Lilly, from his late first love.

Robbie gathers the courage to tell Mary openly, now her lies are exposed, their relationship is over, staying with the family his priority. Simon nurses his broken heart on account of Deenah, refusing to become 'just friends' again. Wilson bonds, while bunking, with Matt and Robby, and demands for Mary to return and go steady in New York, or break up completely. Jeremy forgives Lucy for doubting her fiancé's fidelity. Ultimately Eric helps her transfer to his New York alma mater, near Juliard. The Camden parents finally realize Serena and James are seducing them, ward off each suitor and match the lonely hearts.

Lucy tells Kevin she is thinking of quitting school, and he tells her the wedding is off if she quits. Annie and Eric help another couple face their marital problems and share their own problems. Roxanne leaves the police department.