Timmy and Poof want to watch a horror movie, but are forbidden by their parents to watch the movie. They soon get magically transformed into fly size, and a fly's head gets stuck on Timmy's body.

Mr. Crocker is hypnotized into no longer believing in fairies. Unfortunately, it turns out his belief powered Fairy World's magic. Timmy and his godparents must now find a way to make Crocker believe again, or else Fairy World will lose magic and plummet out of the sky.