Back when we were playing 1e, and my brother wanted to play a drow, he told me that his ambition was to overthrow and replace Lolth as the Queen of Spiders. He labored under this premise for the entire time it took to go through T1-4, A1-4, G1-3, D1-3, and Q1. When the party was at the edge of the final conflict and had Lolth on the ropes, I told him that he had to make his choice. Sacrifice his companions and become the new Queen, or save them and give up any chance of it. He chose to save his companions. They left Lolth, barely alive, to be healed by her handmaidens.
Jump ahead 15 years (real time, about 30 years game time). The players are now playing the children of the original characters. Lolth is back, healed up, and ready for a fight in Queen of Spiders II: Black Queen's Gambit! I reintroduced his original drow character, now a dedicated drow hunter, as an NPC to bring them into the scenario.
Lolth, still smarting from her defeat, has set her sights on Oerth once again, and she has no intent of letting these young upstarts spoil her carefully laid plans! She found a crystal sphere called Darkspace, which was filled with drow elves, and built an armada to take not just Greyspace, but Realmspace as well! The campaign was to take place across three crystal spheres and on several worlds!
Sadly, time just did not allow us to see its completion. We had barely gotten started when I joined the service and moved to California from Mississippi (this was pre-Internet, mind you), and by the time I made my way back home, the bulk of the players had gone on to other things as well.