Polly and friends can't wait to perform their version of a popular dance challenge at the school dance! But on the big night, when someone (or something) tries to sabotage the event, Polly goes tiny to save the school dance.

Polly is cast as Prudence Pocket, but Polly feels she doesn't know what she's doing! Before she can quit the play, Polly and her pals discover a pockite-powered time machine.