Flashback to the night the party first gathered at the Inn in Hommlet ... Elmo is speaking
"So there I was, adventuring with my Brother Otto in the Temple of Elemental Evil. Demons and other foul creatures around every bend, sneaking sometimes, and fighting othertimes. I'm not too proud to admit that we ran some too.
"We weren't the only adventurers in the Temple of Elemental Evil, either. My brother Otto was a Knight of the Hart and an agent of the King of Keoland, set to watch over the wards that trapped the Demon Queen within the bowels of the Temple. There were other groups of adventurers, but you never knew for sure who was backing them and what their real goal was. The followers of the Old One, Hedrack and his crowd, were attempting to use the imprisoned Demon Queen of Fungi in their own foul schemes. The meddling Circle of Eight also had their agents running rampant in the dungeon, especially Robilar the Traitor, who freed the Demon Queen from the final wards in exchange for three wishes.
"After the Demon Queen was freed, all four sublevels were collapsed and buried in stone. Good thing its buried, since there were portals that led to the Elemental planes and to the Abyss.
"The whole place was a maze, with wandering monsters everywhere. We met some adventurers who had been trapped down there for weeks or months.
"Nasty. Gives me shivers just remembering it."