It was an ordinary day for Twilight Sparkle: Magical study, talking with friends, reading a light novel, the usual routine.

But, when something dreadful begins happening to the ponies in a specific region of Ponyville, it was only going to be a matter of time until it spread to the rest of the village; and cause an unavoidable disaster.

Can the studious pony put together the signs and find out what is happening to everypony before it's too late?