A Pathfinder Roleplaying Game adventure for 15th-level characters, this volume presents the epic climax to The Serpent's Skull Adventure Path, in which the heroes lead an army of savages against a threat from the underworld, face a power mad cult of snakemen, and do battle against the half-resurrected corpse of the snake god Ydersius himself. This volume contains details on the decapitated snake god Ydersius, his cult of sinister serpentfolk servants, and his undying threat to the surface world. Additional details on the jungles of the Mwangi Expanse, tribes therein, and other threats from the depths also outline numerous ways GMs might continue their campaign past the conclusion of The Serpent's Skull Adventure Path. Plus, five new monsters in the Pathfinder Bestiary, new fiction in the Pathfinder's Journal, and much more!