While Steven and Elyse are away on vacation, the Keaton house becomes a hotel for the weekend after Mallory accidentally crashes her parents' car into a telephone pole and the kids need to raise money for auto repairs. A lot of people are in town for the Leland homecoming game, so Alex decides to take advantage of the situation and rent out rooms but suddenly he's swamped with renters and the house looks like a three-ring circus.

Alex anxiously awaits a crucial college recommendation from his English teacher and urges Steven and Elyse to butter Mr. Tedesco up on parents' nite at school - but the obnoxious Tedesco is so insulting that Elyse slugs him, and a horrified Alex entreats Steven to make amends. The usually calm and non-violent Elyse is amazed and ashamed at her uncharacteristic behavior, though Tedesco ""asked for it"". Steven visits him and after being subjected to disparaging remarks about his wife, winds up repeating her deed. Finally Tedesco, who does recognize Alex's intellect, accepts an invitation to the Keaton home where he alienates everyone again. Alex must decide whether a glowing recommendation from an influential but disgusting man is worth groveling for.

Steven's assistant at the station is bright, talented, funny, witty...and in love with him. And it looks like Steven may be returning her affections. It becomes obvious that Steven's assistant, Stacey Hughes, is very much attracted to him. And after a rough evening at home, as brief fling begins to look better and better to him.

When Alex takes diet pills for a lift during mid-terms, his dependency level increases daily. Alex is studying for several tests and convinces Mallory to obtain diet pills to help him stay awake. At his hyperness and irritability increase, so does his dependency on the pills. When he finally gets so desperate that he threatens Mallory to get more drugs, she becomes worried that he is headed for a ""crash landing"".

While working as a DJ at the school radio station, Alex strikes up a telephone friendship with caller Lorraine Ferrar, who shares his love of swing music, and he and the attractive 40-year-old meet and develop a special relationship. Drawn to Lorraine's sexy voice and love of swing music, Alex invites her to a Big Band concert. On arriving at her home for the date, he's shocked to find that she's an older woman and the mother of one of his sister's classmates. But they develop a platonic relationship, enjoying each other's company and discovering a wide range of shared interests. When Alex and Lorraine continue to ""date"", Steven and Elyse try to accept it but eventually ask her to stop seeing their son.

Alex courts disaster when he invites two dates to the senior prom and devises an elaborate scheme for escorting each of the unknowing girls on a night to remember. Prom chairman Alex is all set to attend the big evening with an ecstatic Rachel Miller, when he finds that his heartthrob, Jocelyn Clark, has just broken up with her boyfriend. While consoling her, Alex invites her to be his date and finds himself in a major jam. With Skippy's help he tries to juggle both dates, until the truth comes crashing down.

Alex is so sure that he will be named valedictorian of his class that he can't cope with the thought of being defeated by a girl especially his girl so his budding romance with Rachel is threatened when she wins the honor. The dismayed and shattered Alex, who even memorized his valedictory speech, feels cheated out of an honor he felt was his destiny all thru high school and he precedes to sabotage his relationship with Rachel.

Alex is thrilled to be taking a college course taught by one of his personal heroes, Professor Ephraim Bronski, but in his eagerness to impress the teacher he gets off to a bad start and is humiliated by his idol when he fails the first class assignment.

Alex is teamed with long-time rival James Jarrett and assigned to work at a ""hotline"" crisis center to fulfill a course requirement, and the two end up in a crisis of their own when they get a call from a suicidal student. As an economics student, Alex finds it demeaning to be forced into a public service position, but his experiences at the crisis center gives him a new outlook on life.

Alex plays Cupid to help his shy pal Skippy get together with Jane, the girl of his dreams, but his good intentions goes awry when the girl falls for him instead. When Skippy and Mallory find Alex locked in a passionate embrace with Jane, Skippy accuses him of stealing his girl.

Because of Elyse's pregnancy, the family decides to get a housekeeper, so Alex hires the lovely Karen Nicholson, a totally incompetent young lady whom the family immediately adores but Steven insists she must be fired. Despite the fact that Karen has no domestic skills and is rapidly destroying every appliance in the house, the kids love her and Steven has a difficult time trying to fire her.

As the new editor of his school paper, Alex uncovers a cheating scandal and to everyone's chagrin, prints a list of students who were caught including Mallory.

To the dismay of the Keaton children and their equally conservative grandparents, Steven and Elyse take time out Thanksgiving Day to attend an anti-nuke rally-and end up spending the holiday in jail.

Though Alex loves working at Mr. Adler's "Mom and Pop" grocery store, to the old man's dismay, he quits to "climb the corporate ladder" at an ultramodern supermarket.

The Keatons consider buying a gun for protection after getting burglarized.

When a blizzard forces the Keatons to spend Christmas at home, Elyse's gift to Steven, an album filled with fascinating old photos, sparks flashbacks to the birth of their three children.

When pretty Carrie Newman and her mother Julia come to visit the Keaton's, Carrie's forward behavior sends Alex into a panic.

After Mallory secretly submits a picture of Elyse and herself to an ad agency for a mother-daughter modeling contest, she's ecstatic to have won but dismayed and jealous when the reluctant Elyse becomes the star model. Mallory is thrilled at the prospect of entering the glamorous world of modeling, but Elyse must be coaxed into participating. At the photo session, Elyse is showered with attention, while Mallory is shunted to the sidelines. To the chagrin of the teenager, her mother who is becoming seduced by the glamour, is offered a TV commercial for TV dinners to be filmed in the Keaton home. The filming ensues, but Mallory is determined to create a few stumbling blocks.

A cynical Alex finds the spirit of Christmas in a dream, when he's shown shocking visions of the past and future by ghosts of Mallory and Jennifer. While the family enjoys trimming the tree, singing carols and taking pictures, Alex would rather listen to stock reports and finds Christmas ""a silly sentimental farce"" except for the commercialism. That evening, when he drifts off to sleep, Jennifer, The Ghost of Christmas Past, takes him back ten years to a scene in the Keaton living room and a time when young Alex loved Christmas. Next, the Ghost of Christmas Future, Mallory, appears and transports Alex 15 years ahead in time. The impoverished Keaton household is a sorry sight, visited by a rich fat cat on his way to Las Vegas - the future Alex.

Mallory turns to Alex for some advice when she begins to fear she'll lose her new boyfriend unless she agrees to his pleas for a more ""adult"" romance. Sixteen-year-old Mallory and eighteen-year-old Rick seem to have a special romance, and she fears that she'll ruin it unless she gives in to his request to enter a new phase of the relationship. Mallory becomes burdened with the question of what is the ""right time"" for the ""first time"".

Excited at the prospect of reviving her folk-singing career at a local niteclub, Elyse faces the skepticism of Alex and Mallory and an audience unattuned to the songs of the sixties.

When Alex's pal Skippy discovers he's adopted, Alex helps him cope with the shocking news and accompanies the nervous teenager on a memorable meeting with his real mother.

Elyse is stricken with gambling fever on a business trip to Atlantic City, and while on a roll with Alex's "foolproof" blackjack system, she's oblivious to her family and job. Excited at the prospect of having his system put to the test, Alex urges his folks to "go for the gold", but Elyse insists her trip is strictly business. Finally, she's persuaded to try her hand at blackjack. Swept away on a seemingly endless winning streak, Elyse doesn't show up at the architects' convention, ignores her family's needs and casts all financial caution to the wind.

The news that their mother is pregnant sends the three Keaton kids into an angry outburst resulting in a family battle. The children react with panic and outrage at the though of having a baby around, and the Keaton household is in turmoil while Elyse tries to make them see the brighter side of the situation.

Little Jennifer is thrilled about a visit from Scott, a former neighborhood pal she hasn't seen in five years, but her happiness at the reunion is shattered when he ignores her in favor of her older sister, Mallory. To win Scott's attention, Jennifer dresses up in a flirtatious outfit and goes to the restaurant where he is having dinner with Mallory.