Marcia frets her new braces have made her ugly.
Marcia has to wear braces on her teeth for a short period. The effect of the braces on Marcia is more devastating than Carol first anticipates, as Marcia, who is now self-conscious about her looks, believes she's ugly to the world. On their parents' urging, the kids try to treat Marcia like the braces are nothing out of the ordinary, but their curiosity sometimes gets the better of them instead. But Marcia's perception of herself she feels is supported by Alan Anthony, who was supposed to be her date to the upcoming dance but who cancels.
Although he states that he can't go because he needs to go out of town with his parents instead, Marcia believes the reason a lie so as not to be seen with her "metal-mouthed" self. Greg, Mike and Alice make attempts to arrange replacement dates, but a lack of coordination ruins the plan. Then just before the night of the dance, Alan arrives to resume the date... showing off his new braces which he had fitted after an accident with his bicycle.