In the quest "Infiltration" the player is supposed to use the backdoor to gain access to Treva's watch and use the lever to open the main gate. If you don't go through the backdoor and find instead another mean to enter the castle courtyard, i.e. entering the castle from the top of the hill, the quest will not advance. I've cleared up the castle, I've opened the gate by using the lever and came back to the guy by the campfire. Nothing happens.

This quest doesn't mesh with the Companion quest "Retrieval." I did Retrieval first, then found Stalleo at the back entrance after I came out. He asked me to sneak back in and open the door from the courtyard. that activated the Infiltration quest, except there's a couple things wrong. First -- well, Stalleo Sherlock, I just came out the back door. why don't YOU go in the back door to open the door yourself? Second, once I went back through the fort to the courtyard, the door was already open from me going in during the Retrieval quest. The only way to get Stalleo into the courtyard was to activate the lever...which closed the door. Then Stalleo promptly ran into the closed door. So I had to re-activate the lever to let him in. And of course, the question about his family is all messed up. Funniest thing, but when I found them in Retrieval they had no clothes on. When I went back the way I came on the Infiltration quest, they had clothes on. Finally, I never had the option to tell Stalleo I found the family. Seriously broken quest.