Doctor Whooves was looking forward to a long and happy life with Derpy, but lost her. Thrown into a deep depression, he is visited by an old friend, and his life is changed by a transformation of the Doctor himself that breaks all the definitions of who the Doctor really is.

Note: This is an Assassin's Creed, Doctor Who, and My Little Pony crossover fiction, just so that you know why I'm using the crossover tag.