Sombra returns from death to do battle with the caribou, deciding the fate of who rules over Equestria. Will he fight for what's right or to retain his former glory?
Aliens who can travel between dimensions invade Equestria, and in desperation, the survivors must turn to Sombra for aid. However, Spike has his own mission to save the land, while a stranger with connections to the invaders shares a dark secret.