When a Pathfinder team in the godless nation of Rahadoum disappears, the Pathfinder Society sends the PCs to investigate. Deep beneath the sands of the small village of Wadi al-Hesr, a long imprisoned evil—responsible in part for the destruction of an ancient empire—now stirs and threatens the entire region with a deadly plague. Can the Pathfinders survive a sinister game of cat-and-mouse and escape with their lives?