As the heroes track the Cultists of the Whispering Way through the fog-shrouded streets of Caliphas, they lose their quarry - but a dark patron rises with offers of aid and insights into the cult's ultimate evil. He asks only in return that the adventurers put an end to a murderer terrorizing the city's vampires. This leads the heroes into an underworld of endless night, where they must explore the vampires' deadly society and indulge its blasphemous traditions if they're to discover who's murdering the undead. What they uncover is a conspiracy of blood, and a union of evils willing to risk both life and undeath in the pursuit of ever-lasting youth! A Pathfinder Roleplaying Game adventure for 11th-level characters, this volume continues the Carrion Crown Adventure Path, drawing on themes of classic horror stories and RPG adventures long-awaited by Pathfinder players. This volume also includes a gazetteer of the city of Caliphas, revelations of Urgathoa (Pathfinder's Goddess of the Undead), five terrifying new monsters in the Pathfinder Bestiary, new fiction in the Pathfinder's Journal, and much more!