Rannos and Gremag fight. Regardless of which version I'm playing I keep running into a bug regarding the traders fight. It always happens after I fight the assassin on the road. When I confront them with the letter and start the fight they always revert to the dialog after I damage one of them. They just keep repeating the dialog and restarting the fight. I've tried deleting and reloading the game, but it doesn't clear up the bug.
Which version are you running? I submitted a dlg fix for that a while ago, and I could have sworn it was incorporated into the newest load. EDIT: I just verified my dlg fixes were incorporated from v7.7 onward. Here's a link to where I just reposted them: http://www.co8.org/community/index.php?threads/daryks-mods-for-co8-8-1-0.11499/
This happens to me every now and then, no matter which version I played so far. I usually restart the fight a few times and eventually fight works the way it should ("Help me Gremag, let's get out of here" and they disappear).
I believe that you have to leave room for them to exit through one of the doors during the fight. More specifically the door to the left as you face Rannos iirc.