This floor... is the one which is the hardest. For, you see, firstly - it'll be pretty hard for you to leave, seeing as the stairs are surrounded by rocks. And secondly? There doesn't seem to be an exit. The darkness has also made this floor hard to see - but it's an unnatural sort of darkness.

And is that your shadow, moving on its own, in the dim lighting? Maybe it is. Maaaaybe it is.