Across the Battlefield

From the introduction:

This is a single encounter set on a battlefield. Two armies content for control of a fortress, and casualties have been very high on both sides. Wherever there are corpses piled high, there are ravens, there are looters, and there are ghouls. The ghouls emerge at night to feast on the dead. They dig from underneath. How they know where to go, and how they always seem to have a tunnel right underneath a battlefield is a mystery best left unexplored by those that wish to retain their sanity.