“Doc!”

She could only kick so many. Ponies they were. Used to be. Now, they just moaned, growled, and hissed as mind-numbed monsters.

After venturing into zombie-infested Ponyville for some important supplies, Derpy and the Doctor return to his lab. It's a race against time as he tries to find a way to deliver a cure on an epic scale, and Derpy, recently infected, is trapped in with him.