The Secret Triwizard Challenge

"You're right!" says one of the mushrooms. Surprisingly, all the mushrooms agree on this. You've solved the riddle!
But nothing happens. The mushrooms continue to talk, though they aren't bickering about the wizard anymore.
"So, what now?" you ask the mushrooms.
"Mind you own business, kid!" one shrieks, and the others laugh. They go back to talking.
Well, looks like you'll have to go to another place, now that you know the wizard is a professor. Where should you go?