"Old vault means old money, which means pureblood," Bill said, nodding. "Can I look at the map?"
He leaned forward and took a long sip of his tea, wincing a little as he swallowed.
"The first obstacle is just getting and past the front desks. Anyone going downstairs needed a goblin guide before, but with the new security measures, you actually might have an easier time getting through with the wizard security. Polyjuice is the obvious first choice, though their are methods in place to detect it once you try to get into a cell and it recognizes the false form. Griphook might have a better way of getting around that obstacle than me."