Potiphar was on a quest to obtain a vial of blood from a living god, which he hoped to obtain in a cavern beneath the ruins of an ancient city. He believed the god lived in the lowest levels of the city, and was originally a powerful beast that ascended to minor divinity by claiming the worship of degenerate survivors of the city.
Following Potiphar's directions, adventurers found the ruins of an ancient stone city, mostly sunken beneath a swamp. The ruins are known to be frequented by the Men (Thracian Followers of the Dark One), Gnolls, Lizardmen, Minotaurs, and adventurers. The latter have found three entrances to the underworld among the ruins. One is a staircase guarded by the Thracians, which leads to a rope bridge across a chasm. One is a well-shaft that opens up into a cavern roof full of giant bats, and drops down onto a balcony with a sacrificial altar. One is a staircase guarded by the Gnolls, who seem to be allies of the Lizardmen and Minotaurs.