Even though the Gothic 2 Mod Kit has been released recently, there are still modifications that are being built on the original engine. One of those would be a very young modification - Darken Brood (Dunkle Brut in original) - which seems to have an embeded story into the original game. The official site is located here and it has lots of information already. In the meantime G2N has published an overview of the mod with a few screenshots as well, which can be found here