Twilight Sparkle hold a terrible secret! She is a changeling and can never reveal it to anyone. Pinkie Pie also hold a terrible secret! She is also a changeling and can never reveal it to anyone. Rarity, Rainbow Dash, Applejack, and Fluttershy all hold a terrible secret! Which is... actually the same secret. All of the background ponies hide their terrible secret, which is also the same one. Celestia XXIII can never reveal to her subjects that she is truly a changeling queen!
Everyone is convinced that everyone else would never accept their true nature and no one ever suspect the truth: Equestria is the land of friendship and love! Friendship is the big gimmick of ponies! Surely that means that everyone else are ponies and they're alone as deep cover changelings, right? Of course, no one realized that the last full-blooded pony truly died of old age centuries ago, the hive having effectively replaced ponykind. But well, they can't take chances! No way their fellow ponies, who are truly changelings (but they don't know that), would ever accept them as who they are truly (which they'd totally do), right?
Episodic, non-chronological scene format. Mostly meant to be comedic ; serious story arcs will be identified as such and thus, separated from the main scene collection.