Pathfinder Campaign Setting: Hell Unleashed

Break the seals of Hell and unleash ultimate evil upon your
Pathfinder campaign with an unholy collection of devils, cultists, and
worse. Pathfinder Campaign Setting: Hell Unleashed presents twelve
diabolically detailed encounters featuring the slaves and masters of the
infernal realm, including an Asmodean summoning ritual primed to rip open
reality, a lethal Hellknight test of worthiness, glimpses into the soul-markets
of the infernal metropolis of Dis, profane details on the infamous Book of
the Damned, and a march through the fortress of one of Hell's god-like
gatekeepers.
Each entry includes full statistics for running a particular encounter or
servant of evil, details on its history and machinations, ways to use it in an
ongoing campaign, maps of the related site, and more.