The thin man

The clues I usually get are as vague as this one, so I wasn't really surprised. It was easy to find him and to follow him in an empty hotel. He started going down and down and down some endless stairs. "What could happen?" I thought... Well, I should have asked myself another question -and there are so many... Because as soon as I blinked, in the place of the thin man there was a thin woman. Going down and down and down these stairs...