Hard, long, difficult -- take your pick. Any of those words could describe Derpy's day, delivering mail and packages to ponies. She patiently sits inside Mr. Calzone's restaurant awaiting her order. However, a mishap causes the mail mare's delectable deep dish pizza to go to the wrong pony with the recipient's beloved dessert pizza to her.

Derpy, with her oath pledged, sets off to deliver a pizza and claim hers with a bonus. A week's worth of free pizzas, it's probably worth a bit of trouble, right?