After a traumatic trip from some party favors at Pinkie's house, then watching Pinkie strip Dash of her dignity and cutie mark weeks later, one pony quickly slips into a downward spiral of insanity and takes her friends with her. One day from Winter Wrap Up. Inspired by the fanfiction story, "Cupcakes" and the "My Little Amnesia" videos on Youtube, a story of how one quiet little pony goes rogue and becomes a copy pony serial killer. Who's next on her list?