With Celestia's death and Luna's disappearance, Twilight and Cadence are forced to shoulder the responsibility of protecting the Kingdom. The battle against the griffons had been long and arduous, but after years of struggle, they are finally about to push the griffons out of Equestria.

But many questions still remains: Why did Celestia die? Where had Luna gone? And what made the griffons decided to attack their pony neighbours to begin with?

This is the story of a human soldier, a griffin knight, a changeling infiltrator, a mare and her child. All of them are, willingly or not, involved in the Conversion War.