My wife had this problem with her account, and I tried everything they suggested, like changing allegiance and seeing the bartender, but nothing worked. She even checked the quest archive, but it wasn't there. Then she tried switching accounts, but that didn't help either. The whole time, I still had the quest, but then it just vanished. I didn't change my character or allegiance; I was just trying to help her get her quest back. Now I've tried the same things, and we are both stuck. Come on bungie get a grip.