This is kinda a spin off of Agatha Christie's "And The There Were None" Where 10 people were trapped inside a mansion on an island with no way off, they all began to be picked off, same thing happens in this story, but years later, what'll happen?

This is a story about a werepony who is sent on to an undercover task where she is to sabatoge and kill a volunteer regiment of ponies trying kill her herd,but will she be able to bring herself to it?