After a strange dream involving Zombies, Damon is seeing similar signs everywhere he goes in Ponyville. He convinces Callum, Ryan and Sean to go with him to The Castle of Two Sisters to see if the library within can help him.

Twilight, Applejack, Pinkie Pie and Rainbow Dash are also planning a trip to the castle and decide to tag along. After arriving, they realise that they are locked in and everything is blocked off by wood, debris or doors that were not there before. Soon enough, windows are torn down and chalk outlines appear on the walls.

How many rounds can they get through?