58. Gary Gygax - D3: Vault of the Drow (1978)
The culmination of the D series of adventure modules takes players all the way to the Drow city of Erelhei-Cinlu deep in the underdark where they get to finally face the ones responsible for the Giant Alliance above ground, in case they didn't kill Eclavdra at the end of G3, that is (if they did they are supposed to find that she has been cloned).
There is always a tension in adventure modules between making them too loosey goosey and putting little effort into the story being told and being too railroady and not leaving any discretion to the DM. This adventure falls a bit into the first category, while Gygax invents some truly awesome encounters (the Succubus garden being particularly great) and great settings with the detailed vault and city of the Drow, he doesn't really bother that much in connecting those elements. The players get a moody amazing sandbox to play in but little direction as to why they should play in that sandbox. So the DM is going to be thinking very fast on their feet or is going to have to do a bunch of prep work to lead the characters from point A to B to C.
By the end of the adventure characters will find one of the most famous demon queens in D&D, Lolth, the Spider Queen of the Elves, the largest "dungeon" within the module being her fane. However, Eclavdra isn't working for her, she is actually a servant of a rival of Lolth, so the logic behind this boss battle will have to be made up by the DM as there is no indication of it. Should the players manage to get transported to the Abyssal plane where the true Lolth resides they would have to wait for a couple of years to continue the story in 1980 with Q1: Queen of the Demonweb Pits. I'll get to it eventually.
