"You ladies happen to be lucky enough to stumble upon the one place in the school that such a wild wish would come absolutely true. I believe you found the Room of Requirement, or the Come-and-Go-Room. It gives you exactly what you want, no more and no less, if you know how to trigger it to open. I suspect that your searching for an adventure prompted it to give you that adventure." And was there ever a more clever way to use that room? Perhaps not... nothing truly selfish in it, but it gave them what they desired without equivocation.

"And... you brought me the spoils of war, did you?" He gestured at the burden they carried.