Alvin, Simon, and Theodore find a huge attraction to one of Miss Miller's toys. Instead of asking her if they could keep it, they steal it from her attic. Dave suspects that the boys know more than they are telling him so he tells them the beginning of a story but chooses to let them come up with their own conclusions. In the end, they realize the story is really about them and they go return the toy to Miss Miller.
- The title is a pun on the old fairy-tale saying, "Once Upon a Time."
- The Chipettes are mentioned.
- Part of the Halloween Collection DVD.