Elizabeth has been keeping a secret and thought it was safe in her diary. But after carelessly leaving it out in the living room, Alex now knows that her friend wants to trade her panties for thick, crinkly, plastic diapers. It makes sense why Elizabeth is always messy, late for everything and is always getting parking tickets- they're all big girl things, and clearly she is not one, even she says so in her own diary. Alex is ready to give Elizabeth what she really wants and needs: Firm but loving discipline over her knee, and to go back to being a baby girl in diapers. Even though Elizabeth protests and tries to get out of her predicament, she finally realizes that being put back in diapers and being the baby girl of the house is the best thing for her after all.