In an alternate universe where the villains won, Luna is busy living a quiet life in a land far away from Equestria. But one day an old friend shows up to ask a favor of her.
Betrayal, Racism, Hidden Allies and a metaphorical, and soon to likely be literal, noose around his neck. The only Human in Equestria finds himself on the chopping block for a crime he didn't commit and a certain solar Diarch out for his head.
While on a study-vacation in the Crystal Empire, Sunset, Sci-Twi, Starswirl, and Starlight will have to literally confront their past mistakes if Equestria is to survive.