From Wizards of the Coast:
Into the Pit of Madness transports you deep into the Forgotten Temple of Tharizdun, where mad cultists have sounded the Wailer of Tharizdun, the dark god’s iron horn. Now the ground trembles as the Chained God’s aspect struggles to escape. When it does, the Chained God will follow, plunging the world into Eternal Darkness. This campaign draws inspiration from Gary Gygax’s The Forgotten Temple of Tharizdun and The Lost Caverns of Tsojcanth, as well as Monte Cook’s Return to the Temple of Elemental Evil.
