During the Taking Care of Business quest, after collecting the debts from the 3 merchants, I go to meet brynjolf in the ragged flaggon. He eventually gets up to show me what the thieves guild is all about and starts walking to the cistern. I follow him there but once we walk through the door to the cistern he just stops. If you try to talk to him he just says "hmm" and evetually begins to attack me. I've tried using console commands to reset the quest, complete the quest and start the next one but nothing has worked.