Descent into Darkness (3e)
The Second Darkness Adventure Path comes to its explosive conclusion as the heroes travel into a forgotten world hidden deep underground - the Land of Black Blood. There¸ they must contend with the region's monstrous guardians and defeat the drow who would use ancient magic to call down a star from the sky to destroy their enemies on the world above.
"This volume of Pathfinder also includes a gazetteer of the deadly Land of Black Blood¸ an exploration of the demon lords of Golarion¸ a bonus adventure set in the deepest reaches of the underground world¸ and several new monsters from these dark depths.