have you found sted? if yes, go into the forest path before the troll bridge, and try to look for another cave, go through it until you reach out of it, and you will find the farmsted, then you need to do some quest and talking, and then have the opportunity to make other quests.
If you have not found him, GO AFTER THAT DAMN SUCCUBUS, its where he is, of course, after some time you have found her other prisoner.