I'm doing the Axe of Stone quest at the moment, and apparently I have to go down the mines, but the entrance to the second level is blocked by a wall of stone. I've read that the rubble will disappear after "there is a reason to go down there", but I already have the quest in my journal and have spoken to the dwarven councilman, the elf, the king, and the mayor (although I was not able to give him any alcohol). Is there a way to trigger the rubble disappearing?