From publisher blurb:
The gates of Hell have opened. Fiends run rampant across the earth. As kingdoms fall, resistance comes from small groups known as Disposables. Will you survive when your world goes to Hell?
Fringe Campaigns: Soul Harvest is a sourcebook and mini-campaign setting for unleashing Hell on your campaign. Also included are 1 new class, 11 new prestige classes, 12 new feats, 18 new spells, 4 magic items, and 12 new creatures. Plus new rules for alignment, demonic abilities, and more!