"Which dormitories are you keeping the students in?" William asked, giving up on ignoring the squelching noise his shoes were making and firing off a quick drying spell in the direction of his trouser cuffs. "Are you grouping them in the boys' rooms? It seems as though we ought to consolidate them as much as possible if we can." There was that saying about strength in numbers. The House-elves were quite possibly the ones with that currently working in their favour.
Pete was making considerable progress for someone with such short legs, so William added hastily, "To the left, behind the tapestry, hidden staircase to the Hufflepuff hallway."