Upon arriving in Canterlot for the Grand Galloping Gala late, Twilight and Fluttershy find the city in total disarray. With no ponies to be seen and no evidence of the events that have taken place, the two roam the city. They arrive at the castle only to find that Princess Celestia is nowhere to be found and her sister, Luna, is gravely injured. However, shortly thereafter, they discover the horrifying truth of the events that befell Canterlot: a zombie outbreak.

In time, the two fight their way through the city and discover not only the cause of the deaths of thousands but also a secret corporation that designed it.

Note: More characters to make appearances in further chapters.