How do you get past the ancient rock wraith in the Deep Roads?

There are two ways past the rock wraith. The first is simply to accept the deal it offers, but there are consequences in how the rest of your party will view that action, either gaining rivalries or friendship points. Unless you are playing an evil sided character who just doesn't care, this is not a good idea. The other way is to battle it out. The fight itself is not really all that hard if you have a strong party and lots of healing potions. Just concentrate your attack on the Ancient Rock Wraith itself, use lots of power attacks, and having a mage who can enchant your weapons with a nature based staff can really be a big help. The hardest part is the massive area attack that he does after he starts to glow. As soon as he levitates off the ground you need to move your party to one of the corners of the room out of the path of devistation from this AOE attack, then rush back into the fight and start hacking away again. As soon as he falls, the cut scene takes over and takes the party to the cashe where the key to the outside world awaits. Just don't forget to go back after whatever drops the wraith and it's minions left behind after the battle, then take the exit out to the world and return to high town