Four Words of Horror

A few years back, there was a challenge on Reddit to write the scariest story possible using only four words.  Submissions ranged from the gross ("Those are MY guts!") to the humorous ("Wife checked browser history").  So, in honor of Halloween, what would be some four-word horror stories that would chill the blood of even the bravest zookeeper?  Some ideas I thought of - but I'm open to more!

"The chimps are loose" (Insert species of your choice)

"Was that gate unlocked?"

"It's free day... again." (And beautiful weather!)

"Is that stool bloody?"

"Weren't there three yesterday?" (Let the frantic searching begin!)

"We're gonna be short-staffed." (I don't know why this would be scary.  It's the norm)

And, the four words which have heralded so many disasters in my experience...

"Mandatory staff meeting... NOW"

Happy Halloween!