The Elder Scrolls IV: Shivering Isles

Shivering Isles is an expansion pack for The Elder Scrolls IV: Oblivion.

In a new story arc, a portal opens in Niben Bay, Cyrodiil, leading to the torn realm of Sheogorath, the Daedric Prince of madness. In that realm exists an island that represents the madness of Sheogorath himself with its two sides Mania and Dementia. Each side is the exact duplicate of the other but with the difference that one side is pure depression and the other pure (but don't expect it being less deadlier) happiness - which also changes the look and behavior of the NPCs and monsters. But something is happening to the island and Sheogorath is looking for a champion to take care of it: you.

On the Shivering Isles you will find new many new dungeons, items, ingredients and spells which you can of course take back to Cyrodiil as well. Many new quests and questlines await the adventurer of which many rely on the different sides of the Shivering Isles. For instance, one quest requires you to kill an NPC but it is up to you if you kill the one on the Evil side or his exact counter-part on the Good side.

Only the physical retail copies of the game for the Playstation 3 and Xbox 360 versions contain the previous expansion, Knights of the Nine.