Gothic II/Khorinis (Chapter 4)

for a start talk to lord hagen,he will not believe you then talk to ignaraz he will tell you that there are some orcs near lobarts farm,kill them (if you want)then again you have to find the colonel orc,to find him go through the woods near lobarts farm,search for a cave near the castle and there will be some with and the colonel orc aswell,lord hagen still wont believe you you have to do something more.

sorry this is all i knew about this quest,you'll have to find out the rest your'e self

PEACE ^-^