From the introduction:
A 3 to 6-hour adventure for 4-6 level 4 characters.
Having heard about the Necromanteion, the adventurers arrive at the temple, only to find it in mayhem. A demonic invasion is threatening the temple’s very existence, and the heroes are the only thing that stands between the demons and the temple’s destruction. They must get all the help they can, enter the temple, fight multiple fiends, and go deeper into the building. To advance, they must overcome the challenges presented by the temple itself, challenges normally meant to prepare the living faithful for the journey to the kingdom of the dead. At the climax of the adventure, they must defeat the demon Galgadath, a brute who has taken over the adyton, in the deepest part of the temple.