Jennifer develops her first major crush on science lab partner Tim Higgins, the handsome star pitcher of the school baseball team. When Tim comes over to work on their science project, Jennifer is thrilled, but also embarrassed by his open admiration of her academic talents. Believing the adage that boys never like girls who are smarter than they are, she decided the way to keep Tim interested is to play dumb.

Alex sees Mallory and Nick leaving the Keaton residence in the predawn hours to elope, and unable to stop them, follows them to New Jersey where he finds the young couple taking a hard look at their decision. After Nick bumbles around the outside of the house with a 16-foot ladder, Alex makes a desperate attempt to keep his younger sister Mallory from marrying Nick. But they are too much in love to listen. It takes Erin and Mike, another couple, to give them perspective on their maturity.

Nick and Mallory make sudden plans to elope when Steven and Elyse vehemently oppose their marriage plans and threaten to ground their teenaged daughter. During a quiet evening together, Mallory pops the ""big question"" to Nick. They are ecstatic until they learn that the entire Keaton family is solidly against the idea.

When Alex's friend Greg dies in a car accident, Alex is thrown into a state of shock and begins to seriously question the meaning and purpose of his own life. Having been asked to accompany his friend on the fatal trip and refusing because it wasn't convenient, he is overcome by guilt. He tries to fathom why he was spared in the face of such selfishness, and begins to have encounters with Greg's ghost. His family urges him to get help.

Nick faces a serious dilemma when he learns that to teach an art class he must have a high school diploma. Mallory volunteers to tutor him, but it takes the skills of another Keaton to help him prepare for his final exam. When Mallory fails to make Nick understand grammar, Alex finds a unique way to help him grasp the basics.

Mallory is teamed with 66-year-old Margaret Hollings on a college sociology project and fins that she has a lot to learn about honesty, sensitivity and older people when she almost causes the woman to quit the class. As Mallory facves the fact that te widowed senior citizen has her own special problems as a college freshman, Alex takes a special interest in the terms of the last wills and testaments of his parents.

Alex must choose between his friendship with Skippy and allegiance to his college fraternity when Theta Pi Sigma pledges Skippy with the idea of making him the object of a cruel prank. Skippy is desperate to become a member of a fraternity, but in his zealousness he fails to recognize that he is the ""Big Stooge"" of the semester.

It's bad news for the Keatons when Uncle Rob arrives for a visit and announces that he and his wife, Maureen, have split up. News of Robert and Maureen's separation throws the whole Keaton family into an emotional tailspin, despite Robert's insistence that the decision was a mutual one and long overdue. Having always looked up to his responsible and successful older brother as a role model, Steven refuses to believe that Rob's 25-year marriage is really over. Rob, in turn, is dismayed about upsetting the family, but also disappointed by their lack of support.

Distraught that his girlfriend Ellen has gone to Paris on a dance scholarship, Alex desperately tries to find someone to take her place, but finally realizes that falling in love again will take time. Alex mopes around the Keaton house pining for Ellen until Sharon, a pretty waitress, attracts his attention. Once on a date with her however, Alex tries to transform her into another Ellen, with disastrous results.

The emotional roller-coaster continues at the Keaton household with the arrival of Aunt Maureen, Uncle Rob's estranged wife. It seems like Rob has been less than candid when he told his brother Steven that the marital separation had been a mutual decision. According to Maureen, Rob left two months ago,without a word, and has been on the road, trying to sort out his life ever since.

While assisting his economics professor in the final stages of an important research paper, Alex faces a serious moral dilemma when he finds that his mentor's conclusions are not supported by the facts. On the threshold of winning the coveted Wilson Award for his work with economics professor Rhodes, Alex is dismayed to discover that a major error in Rhodes' computations invalidates the professor's theory.

When Mallory brings her new friend, Allison King, home with her to study, little does she expect that Allison will find a kindred spirit in Elyse. Bound together by their love of architecture, Allison and Elyse soon become fast friends, with Elyse even becoming the subject of Allison's architecture research project. They study together, shop together, go to exhibits together, always inviting Mallory to join them, but unconsciously making her feel like a fifth wheel. Matters come to a head when Allison is invited to dinner at the Keatons "" after getting an ""A"" on her college architecture project. Mall unexpectedly vents her resentment and jealousy, and storms out, leaving her mother upset and confused. When Mallory finally does return home, she and Elyse have to deal wtih the conflict that Allison's friendship has stirred. And together, they reaffirm that blood is, indeed, thicker than common interests.

The Keaton's are a house divided over a ""major"" domestic issue whether to redecorate their old-fashioned, but cozy kitchen. Elyse, Mallory and Jennifer think the time has come to leave the familiar behind and opt for a new, more modern look. Steven loves the kitchen's history, and doesn't want to change a tile. Alex only half-heartedly joins the fray. His thoughts are elsewhere, in Chicago to be exact. His employer, Leland Trust, is sending two representatives to the 15th Annual Midwest Banking and Financial Planning Seminar, and Alex is already packing his bags. But he's in for a rude awakening when his boss, Rebecca Ryan, chooses the shy and retiring Matthews over Alex to accompany her to the conference. When Matthews becomes ill, however, Alex is pressed into action. This could turn out to be the professional highlight of his young career. It could also turn out to be the end of his brief career, as he is obliged to ""room"" with his boss for the duration of the conference.

While Steven tackles the job of re-wallpapering the Keaton kitchen singlehandedly, Alex is in Chicago with his boss, Rebecca Ryan, attending an important banking conference. Forced to share a tiny room due to a shortage of hotel space, the two spend an awkward and uncomfortable nite together, with Alex relegated to sleeping in the closet. Getting ready for the conference, Rebecca becomes more and more nervous as she prepares to meet the Federated Bank President Charles Okun, Jr. to try and facilitate a merger between his bank and Leland Trust. Unfortunately, the champagne flows at the banquet and Rebecca proceeds to get thoroughly drunk. To Alex's surprise, she ends up insulting Okun and his young wife, totally blowing any prospects of a merger. Most embarrassing of all, Rebecca ends up making a pass at Alex.

When Mallory comes home from her sixth disastrous date in a row, Alex tries to comfort and then help. He will find her a new and perfect boyfriend using a computer that the Keaton's have gotten for Jennifer's ""educational"" use. Yet, when Roger and Mallory don't hit it off, Alex refuses to give up on getting this ""perfect couple"" together.

Alex shocks his parents when he visits his 3-year-old brother Andrew's very special preschool class, decides the wrong values are being stressed and withdraws him from the school. Steven and Elyse had pulled strings to get Andrew into the special preschool. They are shocked when Alex announces that the school teaches ""anti-competitive"" values, and argues that his brother should be taught in a more aggressive manner.

When Terry Bridgeman, a colleague of Elyse's, confides that he has broken up with his girlfriend, Elyse decides to fix him up with a family friend, the beautiful Liz Obeck. What Elyse doesn't realize, however, is that Liz has been seriously involved with someone else for two years.

Mallory's relationship with Nick is put to the test when she joins a poetry reading group and becomes infatuated with its handsome and sophisticated leader, English grad student Colin Spenser. Newly exposed to poetry and enormously flattered by Colin's persistent attentions, Mallory begins to question the wisdom of being ""tied down"" to Nick. Despite a stern warning about Colin's sincerity from one of his former conquests, fellow group member Joyce, Mallory is swept off her feet by his gift of roses and poetry, and agrees to join him for a special tete-a-tete following an evening's reading. Her perspective, however, is shaken up quite a bit when she realizes that she is, in fact, just the ""next girl in line"" for the all-too-smooth Colin.

When Elyse's sister Michele and her family arrives for their annual visit, Elyse is overjoyed, while the rest of the Keaton clan brace themselves for a long hard week of togetherness. With the exception of Elyse, who loves spending time with her sister, each of the Keatons is hard pressed to be gracious about the situation. Steven is constantly being needled by Michele's husband Marv; Michele's daughter Monica becomes the resident prophet of doom and gloom; and Monica's brother Marv Jr. begins appropriating Alex's clothes. Oblivious to the Keatons' hospitality, insomniac Marv serenades the household with bagpipe tunes late at night, accepts collect calls from his business associates on the Keatons' phone, and generally drives everyone crazy. It is only after he demolishes the back end of the Keatons' car, however, that the usually tolerant Steven jumps up to defend hearth and home.

Alex is emotionally torn when he goes to work in a bank and finds that the vice president to whom he reports is Ms. Ryan, a beautiful, smart and self-confident woman and that he's growing more romantically interested in her each day. The Keaton family delights in Alex's taking orders from Ms. Ryan, but their playfulness wanes when they discover his attitude toward her is taking a toll on his career and ego.

When Skippy falls head-over-heels in love with Mallory's new college friend, Amy Sussman, he's both startled and overjoyed to find himself in his first real romantic relationship. Just as Steven finishes an informal pep talk with the kids, unraveling his fool-proof plan to throw Elyse a surprise birthday party, Amy arrives to pick Mallory up for a study session. Skippy happens to drop by and is immediately taken with Mallory's shy and pretty friend. He's so smitten, in fact, he's rendered completely helpless, and Mallory ends up arranging their first date.

Steven and Elyse are forced to take a new closer look at Nick and his considerable artistic talents when they invite him to compete with other local artists to create a sculpture for the lobby of Steven's television station.

In her quest to become one of the popular kids, Jennifer invites her trendy classmates to her thirteenth birthday party. When they become bored and begin grumbling at her ""lame"" party (which includes a traditional puppet show by her father), Jennifer takes drastic action. With Mallory's guidance, she becomes a ""valley girl"", who then deserts her own party. Yet, it's only a matter of time before Jennifer realizes she isn't having any fun and she rebels against her new friends.

When Steven is asked by an old college friend to help him re-establish a left-wing political magazine they had worked on 20 years before, Steven realizes he is no longer in tune with the radical thinking it reflected and that his values are more middle-of-the-road than he had ever expected. When Matt Gilbert tells Steven he has the funds to revive ""The Scavenger,"" Steven is excited about the opportunity to again express his viewpoints and to vividly recall the college days when he pursued Elyse. It only takes one story for him to realize, however, that he no longer represents the revolutionary left.

When Alex plays "gentleman" to his mother and two sisters and orders for them at a restaurant without even asking them what they want, the battle begins with Elyse, Mallory and Jennifer on one side, and Steven, Alex and Andrew on the other.