After failing to make enough desserts for an important snooty party in Canterlot, Pinkie gets a very disturbing talk from Discord who explains that everyone she knows was just posing to be her friend. A disgruntled Pinkie eventually does something that gives Discord complete and utter immunity to anything. The rest of her friends, unaware of what has been going on, are shocked to see Pinkie do something like that, and then..the fight begins.

This story was originally posted by me on fanfic.net, before I was enlightened by the existence of this website.