The Demon Within (d20)
For years¸ the knights of Mendev have held back the evil locked inside the Worldwound¸ a vast¸ demon-tainted landscape. Every few years¸ they anoint a new protector¸ a sacred guardian charged with pitting his will against the teeming hordes bent on devouring the very souls of the living. This year¸ something has gone horribly wrong¸ and now a bloodthirsty demonic army has overrun the ancient fortress¸ and threatens to pour into the surrounding countryside.
"This adventure is set in Mendev¸ the site of the largest crusade in the Pathfinder Chronicles Campaign Setting¸ but it can be easily adapted for use in any setting.