The Elder Scrolls IV: Oblivion - The Orrery

The Orrery is the second official add-on for The Elder Scrolls IV: Oblivion. It adds a new quest (Repairing the Orrery) and a location. In the quest, you have to retrieve four missing artifacts so that a mage could repair the Orrery which you can later visit to fortify an attribute in the expense of another.