The Doctor crash lands in Equestria. The TARDIS tried to stop it; she didn't do it. The thing is, Rainbow Dash got hit. Literally.
The whole of ponydom is about to come crumbling down unless the Doctor can stop it.
The whole world.
And who will help the Time Lord?
Not really Doctor Whooves, as this isn't following any guidelines of his life. No Derpy, no Dinky. So, yeah. 10th Doctor[/u]. Based somewhat off "Doctor Whooves and the Assistant" though.