Storybooks

"Storybooks" is Episode 14 in Season 5.

Synopsis
Waldo shows up in the store looking for a Robin Hood storybook that has a terrible spell in it. Muffy happens to be reading it, accidentally activates the spell, and ends up in the Land of Make-Believe thinking she's Robin Hood. Jeff, Jodie, Sam, and Waldo must go after her, and there they face the evil sheriff.