The Key

Happy Hump Day! 

Today's Prompt: 
You find a key which opens a door to untold horrors. 


I twist the key in anticipation, not sure what to expect. When the door swings open, all manner of beings rush over the threshold, knocking me to the floor. There's no time to shut the door before every last one is free. Looking out the window, I realize that I've released a plague upon humanity. Demons of some kind are killing everyone. 


Leave yours in the comments below!