From the back of the book: For the past century, the dark god Izrador has ruled with terrible brutality over Erenland. But in the frozen north, the Shadow has held sway for millennia, corrupting all that it touches. The dark god, reborn from his own grave, drains all sterngth and vitality from the land, granting it in turn to his chosen servants. Yet there is life in the Northern Marches, albeit twisted and warped by the dark god's presence. This isolated land, long thought uninhabitable by humans and fey alike, has been a crucible for some of the most terrifying creatures on Aryth. It is the birthing place of the orcs and the harsh realm in which those savage warriors are trained. Likewise, magic itself is corrupted here, and strange new breeds of creatures arise while undead legates and ancient orc crones twist reality itself with the help of their dark master. This sourcebook is ideal for DMs who wish to set a single adventure or a whole campaign in the Northern Marches, or for those who simply desire more insight into the workings of the world beyond the northern edge of the map in the world of MIDNIGHT. Heart of Shadow includes: Expanded detail on the orcs of MIDNIGHT and the lands they inhabit. New prestige classes, creatures, creature templates, NPCs, and rules for the corruption of soul and spirit by the Shadow's taint. A glimpse into the grave of Izrador himself!