In the fifth season-opener, big changes are afoot in the Camden household this fall as Eric is distressed by the fact that his daughter Mary has opted to postpone college in favor of a little soul searching and the glory of minimum wage. Mary decides to buy a car. Also, Annie leaves Eric with a handful at home so she can complete her teaching degree. Meanwhile, Simon attempts to fit in with the treacherous terrain of high school, and Lucy looks forward to ruling the school as a senior. Lucy can't wait to start a relationship with Andrew Nayloss, except he hasn't come back from summer vacation yet. Meanwhile, Heather and Matt's on-again-off-again relationship threatens to be off-again--- permanently. Matt considers the pre-med track at college and Ruthie learns that she will have to spend another year with her despised third grade teacher, Ms. Riddle.

Mary, still intent on her independence, finds herself buried under a number of unpaid bills after losing her job at the pool hall. Meanwhile, ""The Colonel"" (guest-star Peter Graves) surprises Eric and Annie with an unexpected visit. Matt blames everyone but himself for his failing grade in organic chemistry class. Lucy enlists Simon to assist her with her Homecoming Queen Campaign to help him gain popularity in school, and Ruthie's prayers are answered when she's transferred out of her nemesis' class and into a prestigious private school.

Responsibilities fly out the window when Eric and Annie enjoy seperate nights out on Friday. Although the reverend can't find anyone to hang out with him, so he calls a bewildered Matt. Annie is conferring with a professor (guest-star Jeff Yagher). Mary strays even further away from her parent's image of her when she is tempted to drink and smoke one night after work. Also, Mary makes friends with married co-workers Frankie and Johnny (guest-stars Chyler Leigh, Nathan West) with questionable morals while working the late shift. Matt blows Simon's chance at a big date with an older woman (guest-star Katie Stuart) when Matt is distracted by a close encounter of the female kind and forgets to pick up Simon. Also, Lucy gets a taste of the not-so-glamorous side of parenting when her and a classmate take care of an egg.

Tensions run high as a doubtful Julie lets Mary baby-sit Erica, only if Mary has no visitors. But when Frankie (guest-star Chyler Leigh) comes by and begs Mary to take care of her baby Mercy, Mary can't resist helping her. Then, Mary is then caught with an open bottle of beer while babysitting. Meanwhile, Lucy volunteers to chaperone Ruthie's sleep over and to watch the twins. Also, Simon is on a quest to change his image and does this by piercing his ear. Matt pursues a woman who wants nothing to do with him. Also, Eric and Annie clash with Mary's disreputable friends.

Still unemployed and bills mounting, Mary continues her downward spiral to rock bottom as Eric and Annie fight about how to effectively deal with her numerous lies and immature behavior. Meanwhile, the fear of what may happen to Mary starts to take toll on the rest of the whole family. By this, it is prompting the children to break open the twins piggy banks to help Mary pay her bills. To get the credit card company to stop calling, however, they are forced to make a risky decision. During all this, Mary CONTINUES to ignore her responsibilities.

Mary's future may be resolved, but the rumor mill surrounding her situation runs rampant. While ugly rumors spread about Mary's sudden departure, Simon is persuaded to use his sister's bad reputation to boost his 'cool' quotient at school and gets into some trouble of his own with identical twin bad girls, Carol and Sue Murphy (Mary Kate and Ashley Olsen, Full House). Congregational gossip irks Eric. Lucy wrestles with high school hearsay. Ruthie spreads phony tales to draw attention away from Mary, and Matt's infatuated with a beautiful stranger. Also, Annie goes out with an old boyfriend.

Eric tries to arrange a romantic evening with Annie, but Annie keeps turning down every attempt he throws at her. At the same time, Annie takes Eric by surprise with the news that she would like to quit college and to start teaching to help get her out of her depression. Meanwhile, Simon is at risk of being fired from his new job at the pizza parlor by his excessive tardiness and discovering that waiting tables takes more people skills than he's equipped to handle. Also, Robbie sets Lucy on a date with one of his friends while Matt is concerned about a woman who keeps showing up at the clinic a lot. Lastly, Mary performs terribly in fire fighting training distracted by her consuming relationship with Wilson.