Eddie doesn't study for a chemistry test and convinces Urkel to help him cheat (by pretending to have a cold). When Urkel really does have a cold, he is caught giving Eddie the answers and - when he keeps mum about who he was helping to cheat - is threatened with expulsion. Meanwhile, Carl becomes the laughingstock of the precinct when he literally sleeps through a house burglary (thanks to the crooks using sleeping gas). One night, when Eddie and Urkel were confessing their misdeed to Carl, they fall asleep again - only for Harriette and Rachel to nab the burglars in...
Harriette's troubled cousin, Clarence, comes to live with the Winslows until he can straighten out. Instead of deciding to fly right, Clarence becomes a bad influence on Eddie and gets him and Urkel into big trouble when they are caught with a bunch of pretty girls ... and a stolen car! Eddie confesses and realizes he shouldn't have listened to Clarence, whom Harriette quickly becomes fed up with and kicks out of the house.
Estelle wants to share the stories of her late fighter-pilot husband and World War II's Tuskegee Airmen with her family, but nobody is interested. She decides that Eddie's American history class may be more willing to listen (particularly Eddie, after he sees how cool his grandfather was).
A variety of situations involving the gang and home-ec class: Urkel can't cook a lick (and of course causes plenty of accidents); snotty Cassie Lynn finds she can't always be a cover girl all the time; and Waldo learns he may just be good at something after all.
Urkel again tries to intervene in Laura's budding romance with Daniel Wallace, whom the nerd has learned is nothing but trouble. Laura believes Urkel is meddling in her love life and tells him to go away. Then Daniel sneaks into Laura's room and, when he tries to kiss her and she pushes him away, he calls her a baby - just like Urkel had warned. Eventually, Daniel is chased away and a shaken Laura breaks down in her parents' arms.
Laura runs against Cassie Lynn for class president. Cassie Lynn is determined to win any way she can - even if it means publishing photos of Laura and Urkel caught in a compromising situation (he actually was trying to brace Laura, who had fallen from a ladder). So, Urkel decides to fight fire with fire.
Urkel convinces R&B singer Johnny Gill to serenade Laura in the Winslow's living room. Meanwhile, Carl and Harriette try to enjoy their second honeymoon at a resort that's a little too cold for comfort.
Laura had enough problems trying to give Urkel the brush-off. Now, Waldo is the one who's head over heels in love with the Winslow girl ... especially after she tried to encourage down-on-his-luck Waldo.
Urkel is invited to stay with the Winslows when the nerd's parents go out of town ... and quickly causes plenty of chaos. He drives Laura's study partner away, convinces Richie to get into a fight with a preschool bully, and accidentally vacuums up Lt. Murtaugh's fish that Carl was baby-sitting.
A reprogrammed Urkelbot is sent to fight crime, and proves to be instrumental in foiling a serial convenience store robber. Meanwhile, the women find (to their horror) that a new shampoo has caused them to go bald.
Urkel, Eddie and Waldo go on the teen dating show "Dudes," which Laura insists is raunchy and sexist. Urkel easily wins a date with one of the female contestants, but instead uses his live TV opportunity to reaffirm his love for Laura.
"3-2-1, 1-2-3, what the heck is bothering me?" That's the advice Carl decides to heed as he tries to deal with stress-related high blood pressure. But will the tip work when Urkel - who shows off his new BMW Isetta to the Winslows - asks the cop to help him learn to drive?
Rumors fly around school that Laura and Ted had sex on their date. Urkel confronts Ted and his buddies, but gets shoved into his locker, then Laura refuses to believe the nerd when he warns her about the rumors. When Maxine's story about the rumors match Urkel's, Laura decides she needs to salvage her new "easy" reputation and get the truth out in the open.
Eddie is told to take Richie trick-or-treating, but it interferes with a hot date. Richie decides to go alone and gets lost. When Eddie finds out, he goes on a frantic search to find the little tyke before everyone else finds out.
Waldo's fragile self-esteem takes a huge hit when a misunderstanding he caused results in Eddie's girlfriend leaving him. Waldo decides the only way he can cope is to join the Army Reserves. Urkel finds out and insists that Eddie go look for him and apologize before Waldo makes a big mistake. Of course, Urkel, Eddie and Waldo wind up causing a whole lot of hijinks and get on the wrong side of a tough drill sergeant before they can talk things out. Meanwhile, Carl and Harriette deal with a shady repairman.
Just as Richie is trying to deal with pushy 5-year-old vixen Gwendolyn, a determined Urkel pulls his biggest stunt yet in trying to get Laura to go out with him - by sitting on the roof of the Winslows' house and not coming down until she says yes.
Eddie becomes fed up with Carl's strict house rules, and he's not going to take it anymore. Urkel becomes frustrated when his parents make him cease with the scientific experiments (which always cause trouble), and he's not going to take it anymore. The solution? Pool their funds and become roommates in a run-down South Side apartment.