I am kinda stuck in this quest. I am taking the Elf side of the quest and I have made it to the locked entrance to the Werewolves lair. I go around and fight the dragon and eventually I get to that altar with the fountain in the middle and the locked door. I have tried filling the jug of water and placing it on the altar and doing stuff but i cant seem to get the door open or anything. What do i do?