In the wake of a tragedy that resulted in the loss of her sister, Luna took over as the lone ruler of Equestria. Although she has many guards, they pale in comparison to her greatest weapon: the dark force known as Nightmare Moon, who is bound to protect and serve The Night Princess, just as Luna herself is determined to protect her subjects and kingdom.

Suddenly a suspicious rise in violence sweeps through Equestria, as well as frequent attacks on her own life. Unfortunately, the cause may be even more terrifying than anyone could imagine. An enemy long thought defeated has been hiding away in secret, plotting not only to take her vengeance…but plunge all of Equestria into war with the help of a sinister force that rivals even Nightmare Moon's own power.

Strength will be tested, blood will spill…and all nightmares will come true.