The last time there was a murderer in Equestria it was Nightmare Moon. Now it seems somepony new has taken up the hobby. The Doctor stands ready to hunt him down, hopefully he doesn't get into more than he can handle.
Feeling rather unfulfilled, a peculiar teen is given a second chance at life, in the form of Equestria. But things are never easy, upon arrival he discovers he is a changeling! How will he cope? How will the Mane6 react if and when the find out?