From the back cover:
Vast caverns thread the earth beneath the continent of Emer. One of these natural vaults contains a realm of bronze sands and silver grasses lit by a magical sky-roof of brass. Six immortal, evil lords - the Ishru - reside in castles overlooking the deserts and the steppe. They vie among themselves for supremacy, unaware that their holdings may all be destroyed by events set in motion millennia in the past.
Long, long ago, one of the fallen great - a Worldslayer - fashioned Gethæna under the wastelands of central Uj. The vast lava dome housed her demon armies. The hordes were to be unleashed only when her deluded foes foresaw victory.
Gethæna’s creator and all her scheme’s have been forgotten by history - yet her legacy lives on. Within the crucible of the underearth realm, an ancient people struggles amidst the atrocities committed by the Ishru. One man plans to loose these fiendish lords on Kulthea’s surface, while all others seek their destruction.
Treachery, rebellion, and the chances of war challenge adventurers in Gethæna!
Gethæna, Underearth Emer contains:
* A 21" x 16" full-color map of Gethæna.
* A complete campaign involving seven linked scenarios that send adventurers into the perilous heart of Gethæna’s enduring mysteries.
* Details on the Ishru, the immortal fiends who rule the Underearth Realm.
* A history of the ancient conflict between the dark Ishru and their neighbours, the mortal Dain Sædhu.
* Legends from the birth of the world.
* Flora, fauna, and beasts unique to the Underearth Realm, including the savage gleamtiger, soporific sorrow moss, and the bloodthirsty Nuld - minions of the Ishru.
* Politics and power: who pulls whose strings, and the web of intrigue that enmeshes all - the rulers and the ruled.
* Maps and layouts for all adventure sites.
* Complete statistics for all NPCs, monsters, artifacts, and poisons.
* New spell lists for the Ishru and those foolish enough to study under these cruel lords.