Queen of the Demonweb Pits

Q1: Queen of the Demonweb Pits is an adventure module for Advanced Dungeons & Dragons 1st edition, in which the party travels to the Demonweb Pits of the Abyss and battles Lolth, Demon Princess of Spiders and Goddess of the Drow. It is canonically the sequel to the Drow Trilogy Adventure Path, making it the ultimate conclusion of the campaign/super adventure known as Queen of the Spiders, after its omnibus format.

This module's Demonweb is three interlocking Moebius-style strips of pavement, in a plane where geometry itself is not on our side. The pavement is made of the damned; they carve tunnels in the Elder Chaos. The party needs to get under those strips to the fourth layer. The top three connect to interdimensional chambers, like rooms in a dungeon. The last layer connects to whole new worlds, or maybe planes, in the Prime Material. Here the party learns that Lolth has schemes on many worlds, some of which schemes have basically won.

Among the planes is Caer Sidi from "Three Hearts and Three Lions", and a pink ocean which will appear again in 2e classic Die, Vecna, Die!.

The Demonweb was the template for other multiversal nexi, like those in Beyond Countless Doorways and Planescape.

But then comes Lolth's lair itself which is meh.