When a bored Princess Patricia Priscilla makes her chambermaid switch identities with her so she can attend the village school, her attitude changes and she plans a new way to celebrate her sixteenth birthday.
A.J. is planning a big birthday to celebrate turning 9 and his parents even hire a party planner named Mr. Marty. Mr. Marty orders some weird stuff to celebrate though.
Excited for Papa's surprise fortieth birthday party, the Vanderbeeker children learn more about their mysterious grandparents while waiting for the celebration to start.