Nemnok the Devourer (quest)

 is a side quest in.

Synopsis
The Junvik people speak of Nemnok, a mysterious god whose lair is in the depths of the Drowned Barrows. Nemnok takes offerings from the tribe, most recently a boy named Kaali.

The prospect of a new god is troubling at best. Unless "Nemnok" is merely some new aspect of Skaen or Wael playing tricks on the world, the matter bears closer scrutiny.

Walkthrough

 * The goal of the quest is to reach the Sanctum in the Drowned Barrows. Approach Kaali, who will then summon Nemnok the Devourer into the world. Nemnok will then introduce himself and demand your supplication after Kaali introduces you as the newest sacrifice. You can tell him off with Intimidate 18, or question him on him being an imp. You can then use Diplomacy 8 to receive the quest to deliver Nemnok grimoires. In doing so, you also secure Kaali's release - though he will be nonplussed.
 * If you do not have Intimidate 18, you will be forced to fight Nemnok and Kaali. After the fight, you can convince Nemnok to come along as a pet (which provides +1 to empower and +1 casts of level 1 druid, priest, and wizard spells). During the fight, its possible to leave Kaali and many of the worshipers alive even if they attack you; just down Nemnok and combat will end.
 * Note that it is also possible to agree to help Nemnok, which frees Kaali; then, you can attempt to take the treasures he has as reward for The Lost Grimoires - the chests are not even locked, but will aggro everyone in the chamber. This way, you can get both the treasures and Nemnok as a pet (while saving Kaali to boot). This will actually cause you to fail The Lost Grimoires, though.
 * Return to Tatok.