The Elder Scrolls IV: Knights of the Nine

The Elder Scrolls IV: Knights of the Nine is an expansion pack for the role-playing video game The Elder Scrolls IV: Oblivion. The Microsoft Windows version is available either as a downloadable plug-in from the company website or as part of the retail-released Oblivion Downloadable Content Collection CD—a release that also includes all previously released official downloadable content available for Oblivion. The Xbox 360 version is available via Xbox Live Marketplace, and the PlayStation 3 version of Oblivion includes Knights of the Nine in its packaged release.

Source: TheGamesDB