In an interview with Mark Nelson, Lead Designer at Bethesda Softworks, the staff at Actiontrip were able to tap into Bethesda's drive to create an expansion to the already successful fourth epic story into the Elder Scrolls Legends for the PC, PS3 and Xbox 360.

Bethesda is proud to have developed and completed a game accepted by many, and finds themselves a challenge to do even better than what they have achieved so far. So they began immediately on an expansion to The Elder Scrolls Legend IV: Oblivion.

And unlike Morrowind's expansions, the game does not require the new player to complete or do the quests in the main game. It allows a player to dive directly into the story of the Sheogorath's realm. Of course, avatars that have completed most of the main quest will have little problem going through the expansion's story.

The story of Shivering Isles is a much more focused one, giving more background and more life to the people who inhabit the region. There are much deeper plots to unravel and each now has a much more complete story behind them. The AI, however, while acceptable still has "a long way to go."

Nelson describes the story behind Sheogorath and the Shivering Isles:

Sheogorath is the Daedric Prince of Madness, one of the incredibly powerful beings in the Elder Scrolls pantheon. When the player encounters him, Sheogorath is in search of a champion—there is an impending threat to his realm, and (because of the nature of the threat) he needs a mortal's help. The player will need to rise in the ranks of the Court of Madness in order to earn the respect of the citizens of the Shivering Isles and eventually repel the threat.