In the wake of an almost successful invasion from Equestria's twin reality, it will take the land a long time to recover. Lives were lost, livelihoods crushed, and trust broken. However, the royal sisters restored order after the mirror world army disappeared without a trace, and peace seems to be blooming again. Only two questions still remains: How and why the invasion ended?
With no witnesses of mirror king Sombra's fall, the only clues to solving the puzzle are a patient in the Ponyville Mental Asylum and an ex-Nightguard who left her home and job to move to this small town out of nowhere.