You get into an elevator, and a man walks in behind you, pressing the button for the floor beneath yours. When the doors open, he tells you, "I'm going to kill you when you reach the next floor."

It's not being killed that's the scary part, it's being in there for that short amount of time knowing that death is waiting for you and there is no way to escape.

■■■

I think this is a pretty good story. :O Thanks to @AngelCoffee64 for this suggestion! ♡