"Lestrange, huh?" Bill said, taking the map and scanning it. The location looked right, at least. "It's going to be hard to get down there, especially to that section. Even if Polyjuice won't fool a vault, it'll fool the staff."
He thought for a moment and his eyes suddenly widened.
"There's a back employee entrance to the building," he said. "Sometimes, if we have high-profile clients, they'll be escorted through there by staff. If there were some way for you three to be disguised as an old blood family and their financial planner or something, I imagine I could walk you through there quite easily. I have enough contact with these groups through my department that a meeting with some old money about their estate planning wouldn't seem out of place."
He studied the map for a few more seconds and then tapped his finger on the box representing the vault.
"This is where we'll run into trouble. Griphook will raise suspicion if he's walking with us. We'll need to disguise him in some way that'll keep him unnoticed until we get down there, and then he'll have to do the work of getting into the room."
Glancing at the closed study door, he asked, "Is he around, do you know? It might be good to pick his brain about some of this, and I've got a proposition to discuss with him anyway."