In Risen 2 you meet him in Antigua and then you get the option to let Patty navigate to the Isle of Storms. This is where the main part of the DLC takes place. Afterwards you need to visit five (IIRC) of the islands/regions in the game to complete the DLC for good. You need to find some Gargoyles and their eggs, kill the Gargoyles and take the eggs to Eldric. That's it. Pretty unspectacular on a whole. - At the end of the game Eldric tells you that he will travel to Caldera to continue his studies in the library there. To me that sounded like a fairly strong hint that there might be a full blown expansion.