Lawrence, the prodigal eldest Cleary son, returns home from the seminary and breaks the news to his family that he's dropping out for good, leaving Mike and Peggy upset and wondering why. Meanwhile, Timmy decides he wants to audition for a children's theatre production but when Peggy finds out where it's being held she forbids him from participating. Elsewhere, Eddie tries to keep his girlfriend a secret after Frank finds out and tries to blackmail him.
To Peggy's dismay, Timmy decides to enter a poetry contest to win the money he needs to repair his ventriloquist dummy. Stumped, he decides to plagiarize a poem and soon realizes he's not the only one who passed it off as his own. Meanwhile, Mike and Lawrence continue to butt heads when Lawrence complains that there are no fresh vegetables in the family's diet.
After Mike proudly introduces a new microwave to the Cleary household, Peggy immediately rejects it as she feels like it's intruding into her domain. Fed up with Mike's experimenting and nudging, Peggy secretly sabotages his happiness. Meanwhile, eager to see "everything" exposed for the first time, Joey and Timmy go to extreme lengths to see Barbara Eden's wardrobe malfunction on a Bob Hope TV special. Elsewhere, Lawrence attempts to apply lessons from a psych class at school to psychoanalyze Mike and Peggy, only to realize he needs to look deeply at himself.
To hide a mess Eddie made, his girlfriend, Wendi, tries to distract Peggy by insisting she take a day off with a fun day out while they take care of the housework. To everyone's surprise, Peggy accepts the offer and requests Wendi tag along, with the ulterior motive of teaching her a lesson. Meanwhile, Eddie enlists the help of his brothers to clean up and keep Mike out of the house while Wendi and Peggy are out. Elsewhere, Pat introduces Timmy to his secret dog.
Frank announces he has decided to compete in the church boxing tournament. When Frank can't cut it, Timmy steps in and takes up boxing in order to bond with his dad and get his approval. Elsewhere, feeling rusty after being at the seminary for so long, Lawrence asks Eddie to help prepare him for a date by taking him on a "practice date".
Mike comes to the conclusion that Eddie is being sexually active and takes it upon himself to give him enough advice to work things out. Later, Peggy disagrees with how Mike handled the situation and they argue over how much they should interfere in their children's lives. Elsewhere, Joey and Timmy attempt to disrupt Frank's plan to do free yardwork so that they can go back to getting paid.
Mike and Peggy think they might be expecting again, but later Peggy is diagnosed with having a cyst instead. The experience launches them into a debate about whether or not they should have another child. Meanwhile, the kids spy on Mike and Peggy to try to figure out what all their unusual behavior is about. When Pat overhears that they are going to have a little sister, the Cleary kids decide to dig deeper and continue their investigation, which only leads them on a downward spiral.
When Peggy's successful brother, Tom, drops in for Christmas, Mike immediately oozes with jealousy. Thus begins Mike's one-sided competition with Tom, using his kids as pawns to help. After Tom gives the Clearys an extravagant Christmas gift, pride prevents Mike from taking it - putting him at odds with the rest of the family. Meanwhile, Timmy mistakenly receives 0 from his great-aunt for Christmas and contemplates whether he should do "the right thing" or keep it. Elsewhere, Eddie forgets to get Wendi a Christmas present and panic sets in.
The Cleary boys beg Peggy to tell them she loves them, so Peggy posts a ranked list of their names on the fridge in the hopes that someone will divulge who broke the dining room light fixture. Timmy incriminates his brother but feels so guilty that he gets a horrible stomachache and heads to the hospital. Back at home, Mike invites Grover, a co-worker, disguised as an amateur detective to their home to help compel a confession out of the guilty Cleary child.
Against Peggy's wishes, Frank secretly helps design a set for a musical in which Timmy is performing. Feeling jealous of all the positive attention Frank is getting for his work, Timmy devises a plan which forces Frank to admit his involvement on set, but Timmy's scheming backfires. Meanwhile, Mike grows increasingly concerned that Joey is heading down a shady moral path with all his wheeling and dealing, and decides to teach him a lesson.
Eddie becomes distraught when Wendi breaks up with him over disagreements on how they want to handle their future. Meanwhile, Mike struggles to address Eddie's heartbreak, and Peggy contemplates whether she has to break up with Wendi too. To complicate things further, Joey convinces Frank to send Wendi a love letter, pleading his case as to why she should be his girlfriend. With Frank's impending humiliation on the horizon, the Cleary boys try to help him retrieve the letter and just end up getting into more trouble.
The Clearys feel conflicted when Lawrence and Eddie are drafted to serve in the Vietnam War. Although Eddie and Lawrence try to avoid going, they come to terms with their fate, but the events of the day weigh heavily on Peggy and Mike. Though they are both proud, Mike and Peggy take matters into their own hands and try to derail Lawrence and Eddie's decision to serve their country.
To inspire Timmy to take better care of his personal hygiene, Peggy decides to take matters into her own hands and tricks him in hopes of solving the problem. Meanwhile, a concerned Mike fears that Peggy's meddling is causing Timmy to develop insecurities and robbing him of his passion for performance. At school, Timmy receives a Valentine's Day card from a secret admirer and becomes unnerved by the possibility of having a mystery suitor. Elsewhere, Eddie reports a recurring incident to Wendi's boss in an attempt to be helpful, but his chivalrous deed backfires.
Mike and Peggy are stunned when they learn that Father Dunne has a girlfriend; Frank loses the church keys entrusted to him and must find them before anyone else does.
Peggy's talent for reusing wax from old birthday candles to create new ones lures her into exploring an identity outside the home for the first time. Her newfound candle-making work takes up more time, prompting Mike to get angry that her focus is straying from the family and the domestic duties. Meanwhile, Timmy is determined to get audience tickets on his birthday for a taping of "Boxcar Billy's Hobo Jamboree" in the hopes of making it on TV.
Mike and Peggy are sympathetic when Wendi's parents split up until Peggy realizes that Wendi's parents left her in the house alone, giving her and Eddie an unsupervised love nest. Elsewhere, Joey goes undercover to enter a cockroach he found in a race at a nearby bar. Meanwhile, Timmy is determined to watch the Jerry Lewis Telethon no matter what obstacles come his way.
To fulfill his showbiz dreams, Timmy enters a contest to appear on "The Partridge Family" and takes matters into his own hands when he doesn't hear back. Elsewhere, Peggy takes a driving test in order to get her license, but anxiety sets in and things don't go according to plan. In secret, Peggy tries a few questionable shortcuts to becoming a legally licensed driver, and in the process, drags the Cleary kids into her web of deceit.
After a mishap at the grocery store, Peggy storms out of the house without explanation, leaving Mike and the boys wondering which one of them set her off. Meanwhile, Mike thinks he may be the culprit who sent Peggy away for not signing an application for a credit card she wanted, and he enlists Wendi to help find her
Peggy manipulates William into joining the church choir to keep him engaged in Catholicism; Eddie and Joey are determined to get a hold of Led Zeppelin tickets.
Peggy discovers that Timmy has a newfound and inappropriate hobby and urges Mike to talk to him about it even though he is reluctant to do so. Despite being uncomfortable, Mike attempts to have a conversation with Timmy about the topic and enlists Lawrence's help in the matter. Elsewhere, Frank is determined to finally catch Joey in a lie.
Peggy's competitive side kicks in when she learns that Helen's husband's professional accomplishments are getting high recognition, so she decides to get Mike into the limelight. Elsewhere, always seeking glory, Joey acts as Timmy's manager to make sure he performs his magic act at the Pioneer Day Carnival, while Eddie is determined to prove to Frank that the carnival games aren't all rigged.
After learning that donations are down at their church, Peggy grows concerned that the cutbacks will affect the nursing home where she is secretly housing a close relative. Mike and Peggy blame the low donations on Father Abdi and disagree with him about how to raise funds. Meanwhile, Joey pet-sits his friend's snake and, in true Joey fashion, uses the snake to his advantage.
Peggy struggles with Lawrence's decision to move out of the house, especially after she discovers that he is secretly moving in with a girlfriend she's never met. Lawrence's determination to keep Peggy out of his personal life only causes her to investigate further, while Mike welcomes his departure. Meanwhile, Timmy can't find his ventriloquist dummy, Knuckles, and learns that Joey took him without asking.