The adventurers have either worked their way down through the Green Canyon, a deep subterranean rift, or they have successfully activated an ancient teleportation device – in either case, they have now entered the Under Realm region known as the Cyclopean Deeps. They stand at the threshold of this unexplored wilderness of unlit caverns, a whispered legend in the world of the surface. As veteran explorers, the characters know better. Although there is untold treasure in these miles and miles of sinuous tunneling, there are unknown threats and terrifying foes to be found in these regions as well. Not all is as it appears.
The gateway to the Cyclopean Deeps is Hex 3H, which contains the legendary fortress of Ques Querax, a brutally-enforced neutral ground in the feuds and wars of the Under Realms. The ruler of Ques Querax is The Eye of Gaaros, a gem-like artifact that is the last remaining fragment of the titan Gaaros. Considerably more information about the Eye, its history, and its most unusual project is provided in the key to Area 3H–15, the Eye’s Palace in Ques Querax.
Although the Eye itself is quite powerful, its ability to hold and dominate Ques Querax is largely due to its relationship to the alien-minded khryll, bizarre intellects of the deep subterranean world that seldom cooperate with other races. The Eye keeps three or four khryll in the fortress at all times, and the combined strength of the Eye, its normal guards, and the khryll has thus far offered a powerful defense against both treachery and invasion that the Eye has remained as ruler of the citadel.