"The expanded version of the story from the original Gothic II, told by the addon, introduces a new world called Jharkendar. Situated in the northeast of Khorinis, Jharkendar is presented as an ancient, deserted city. The player helps the Water Mages, also present in Gothic, but which were missing in Gothic II. open a portal, found in an old temple in the land of Khorinis.
The expansion does not bring many significant changes to the gameplay. However, a major change can be seen in terms of difficulty, where the developer had rebalanced the whole game, and made it harder, this after being requested so by the community.
Source: Wikipedia, "Gothic_II:_Night_of_the_Raven," available under the CC-BY-SA License.