In the alternate timeline where Sombra was not stopped, a human finds himself suddenly in Sombra's body... just after the dread tyrant has conquered Equestria.

Framed as a guidebook for humans trapped in the bodies of evil overlords, here lies the tale of a human in the body of Grogar, locked in an alternate timeline dominated by Nightmare Moon.

Seriously, why would any pony be imprisoned for that long?

This is a short story about Starswirl The Bearded. It is also a story about an Earth Pony. However, this not a story about two ponies.