A seemingly wealthy pony by the name of Scarlet Rose decides Ponyville seems like the perfect place to settle down. She appears warm and welcoming enough and quickly begins to blend in with the rest of the ponies around her, even if her choice of home sticks out like a sore hoof on the edge of the simple farming town.

A few days after her mansion is built and she settles in, a hoofful of ponies begin to seem a little sick and have trouble with so much as getting out of bed. Surely it's just a coincidence, right?