Abigail and John Templeton find themselves at TAPAS (the Thespian Academy of the Performing Arts and Sciences) where their father, the illustrious Professor Templeton, has been hired to invent a groundbreaking theatrical device. Once again, there is drama (of course!), silliness, and suspense, as the twins must thwart the dastardly Dean brothers in order to save the invention as well as their father.