Doctor Sparks has never believed in ghosts, and the stories about Canterlot General Hospital being haunted by them didn't discourage him at all from taking on a position there as assistant chief of surgery. But when he awakens one night to a lifeless building filled with inexplicable and horrifying creatures, the doctor is forced to reconsider everything he thought he knew about the hospital, his beliefs, and his own mind. Because at Canterlot General, the past has a way of creeping up on you. Because at Canterlot General, sometimes the present and future do too. Because at Canterlot General, there are things that haunt you, things that hunt you, things you can never truly escape from.

Because at Canterlot General, everything loops.

[Originally written based on the /fic/ Writeoff prompt "Time And Time Again".]