Hard times bring distress for the unemployed Harriette and for a homeless and eccentric janitor [ Poston ], who get s trapped in the school bomb shelter with Good Samaritans Urkel and Carl.

Steve is put in charge of building the school's homecoming parade float. With some difficulty, he gets volunteers to build a beautiful float. Unfortunately, while transporting it to the school, Steve crashes the float and destroys it. Although the volunteers are upset, they realize that the happy memories and friendships developed while building the float will last forever. Meanwhile, Mother Winslow sustains a series of minor injuries in her strenuous hobbies, including karate and square dancing. Carl worries that she should slow down in her old age before she really hurts herself.

The school prom brings one disaster after another for Laura. First, her date cancels; then she's parked with a dateless Urkel at the dance. The group ""Immature"" performs.