When Laura tells Steve to be less annoying, he creates a potion that transforms him into a suave, charming man. But his new attitude soon causes more problems than it solves.
After Laura gets fed up with Steve Urkel's clumsiness and annoying behavior, along with his social ineptitude, she tells him that he needs to change. Steve tells her off that he like being himself, but can't be that way if she tells him to change. He ends up staying away from the Winslows for a week. During this time, Carl is enjoying the week off and even wants to go shopping with Harriette
As a result, Steve creates a potion that would amplify his dormant "cool genes", the consumption of which would eliminate his clumsiness and fix his physicality, including curing his eyesight, while also altering his personality. In order to become a man Laura would like. Steve drinks the potion and becomes Stefan Urquelle, an ultra-suave, confident man who immediately wins Laura's heart.
As Stefan, he becomes the most popular guy in school and the gains the affection of all the girls, with his family even loving him and finally introducing him to his relatives. During a party held at the Winslow house, Stefan interacts with Eddie, Harriette and Carl. While Eddie wishes to be his close friend and Carl appreciates Stefan's presence and compliments, Harriette is skeptical on his sudden change. Stefan then dances with Laura, who is thrilled with his presence and demeanor, and after Stefan kisses her, she grabs him and kisses him passionately as the partygoers cheer.
Now dating Laura, his arrogant, narcissistic traits begin to show, with the turning point being when he seemingly shows no remorse or feelings after one of Carl's fellow police officers was shot during a routine traffic stop. As much as Laura prefers Stefan to Steve, she does not like that Stefan cares mostly about himself. When she hears him insult Steve by calling him a village idiot and a clumsy fool, Laura is really annoyed by this. She tells him off to return as Steve at once, pointing out that while annoying, he is more caring and compassionate towards others. Stefan states that while he enjoys finally being cool and popular and prefers being Stefan Urquelle to Steve Urkel, it isn't worth it if Laura doesn't love him.
Biting and swallowing a tablet that serves as the antidote to his potion, Steve Urkel's personality and physical traits begin to reassert itself while clashing with Stefan's, until Stefan/Steve collapses and Steve re-emerges. Steve immediately tumbles over the couch, and Laura tells him that she is glad to see him again, despite him being annoying. Steve claims that it wasn't a very nice thing of her to say, but she immediately hugs him, prompting Steve to immediately forgive her. She claims that she never wants to see Stefan again after what she went through. Steve reassures Laura that his personality can be improved on.
- Reginald VelJohnson as Carl Winslow
- Jo Marie Payton as Harriette Winslow (credited as Jo Marie Payton-Noble)
- Rosetta LeNoire as Estelle Winslow (credit only)
- Darius McCrary as Eddie Winslow
- Kellie Shanygne Williams as Laura Winslow
- Bryton James as Richie Crawford (credited as Bryton McClure, credit only)
- Jaleel White as Steve Urkel / Stefan Urquelle
- Shawn Harrison as Waldo Geraldo Faldo
- Charles Carpenter as Flirting Customer
- This episode marks the first appearance of Stefan Urquelle.
- This is the only time Steve changes into Stefan by drinking a potion. In future episodes, Steve would use the Transformation Chamber to become Stefan.
- The song Stefan and Laura dance to is "For the Cool in You" by Babyface.
- Jaleel White did not want to do this episode because he felt that the Stefan character was "boring" and "'a one-note joke". However, he also stated that this episode is a favorite of his as well.
- During the party scene, Carl is clearly seen standing on the steps like a security guard, but when KC runs into the house, Carl is nowhere to be found on the steps. He later exits the kitchen with Harriette, holding a tray of sandwiches.
- Urkel: Laura, this elixir will improve my coordination, my posture, my vocal intonation, and I might even sprout a chest hair or two.
- Laura: First you better sprout a chest.
- Stefan: Steve? Steve who?
- Laura: Steve Urkel. You.
- Stefan: No, no, no, no, no. There is no Steve here. I'm Stefan, sweet thing. Stefan Urquelle.
- Harriette: Are your parents happy with the new you?
- Urkel: Oh, they love the new me. In fact, they finally introduced me to my grandparents.