For whatever reason, at the bottom of the stairs, the large stone door leading forward is shut tight.
An amorphous burning thing slithers out from under the door and gestures to part of it. Its flames illuminate a stone tablet that reads "Not open yet. Come back later."
"Don't make me tap the sign," the shifting flame says in a voice that menaces with the crackle of charred matter.
...You're going to have to come back later.