A repackaging of modules D1 and D2 from 1978, now with a color cover and a couple of new paragraphs explaining the place of the adventure in the wider campaign (after the G1-3 and before the Q1) which eventually would be published all together as GDQ 1-7 under the title Queen of the Spiders supermodule in 1986. So nothing new here, you can backtrack on this account to 1978 and take a look at D1: Descent into the Depths of the Earth and D2: Shrine of the Kuo-Toa for more details!