In a totalitarian empire from Equestria's middle ages, four imperial soldiers search its unseemly depths to hunt down some rebels.

The Equestria of a thousand years ago was a startlingly different world from today. Monsters freely roamed its geography by the droves, and ponies depended upon order and strength to protect their daily lives. Anointed by crystals of magical anomaly, the most powerful unicorn governs a mighty empire that would overshadow the world. In spite of his propaganda, unrest and danger still lurk beneath the veil of his fortress kingdom.

Four unlikely novices are tasked with routing the rebel factions that threaten the sanctity of the Crystal Empire. In a world that does not yet know of the Elements of Harmony, what could they possibly find that will enable them to survive the dangers that await them down below?