Feyhall

From publisher blurb:

The residents of Feyhall live barricaded underground within the caverns of an ancient fairy hold in the Fey-Cursed Hills above the Twyll River delta. While the plague infested hungry dead, threaten from without, these rogues and treasure hunters dig deeper looking for the source of the strange lights and music haunting their haven. Food is scarce and what few supplies available are usually stolen from travellers or other nearby settlements. It is a lawless place where residents must be constantly on watch for not only ghosts of dead feyfolk, but also a knife in the back from their so-called allies.