In this Underswap AU, Derpy and Doctor Whooves have completely traded roles. Instead of being an accidental time traveler, Derpy is the brilliant yet endearingly erratic Time Lord of Ponyville who operates a quirky, temporal-displacement laboratory. She still possesses her signature crossed eyes and her all-consuming love for freshly baked muffins, but instead of delivering mail, she spends her days trying to calculate how to fit the entire space-time continuum into a muffin pan. She can be found tinkering with paradoxes, fixing temporal tears, and getting blissfully lost in her own scientific musings while remaining incredibly sweet, cheerful, and loyal to her friends.