[Ah... true. But, that would require Tamamo to give into the idea that she was being dumb, which she rejects immediately.]

I suppose that could be worth a shot. Though, there doesn't seem to be anything here but walls and walls. [Then again, she hasn't looked at all... she starts poking around at the building, looking for any tile that looks out of place.

Because you need to press on secret dungeon tiles to open the magical staircase, right??]

Ohoh! [Her fox tail suddenly straightens up immediately.] This dust! A-achoo!

[That's a hint, though. If there was a staircase randomly popping up, there shouldn't be dust. Should they look for a conspicuously clean spot?]