When you get to the Selune temple filled with goblins, there is a room with three goblins. One has a thunderwave arrow and, if you are crossing the bridge entering the room, it can knock your characters off the bridge. Characters that get knocked off the bridge are teleported back to camp. This killed my character, leaving him at camp, and sent Astarion back to camp. I think the others made their wave or were out of the area of the spell. I used a scroll of revivify on my character and clicked "leave camp" in fast travel. The next thing I knew, however, both my character and Astarion were dead at camp. I think what's happening is the thunderwave arrow knocked Astarion and my character out of bounds and, when I went to return to the last area I was, it spawned me out of bounds, thus killing my character. That is just speculation, however.
