I have run this a couple of times, and I am unable to destroy the Crystal thingy by Wayfinder Dael (the prisoner). No matter where I stand to target it, my ranged weapons just act like they are hitting an obstacle in the way. I have tried mouse-look mode and jumping while shooting. I have tried jumping and melee/attacking it. Nothing I do works, so I can't get the chest in the cave. That IS a chest in there, isn't it?
So what's the trick?
Thanks in advance!