it is the seventh module in an epic series of adventures set in the world of greyhawk, beginning with raids by local hill giants and other events described in the g1-3 "against the giants" modules. the series becomes an odyssey into the underdark, as described in the "drow" series of modules: d1 ("descent into the depths of the earth"), d2 ("shrine of the kuo-toa") and d3 ("vault of the drow"). d1 and d2 were later compiled into a single adventure, d1-2: "descent into the depths of the earth". this module sends the player characters to the abyss to defeat the evil demigod lolth of the drow.