The Elder Scrolls IV: Oblivion - The Vile Lair

About

The Vile Lair is the sixth official add-on for The Elder Scrolls IV: Oblivion. It adds a new quest where the player has to buy all upgrades to the Deepscorn Hollow hideout (also added by the DLC), after which it becomes the player's property. The add-on also adds some new items and a new merchant to the Wawnet Inn.

Source: IGDB