Your hired to work at a hotel and choose who enters and who doesn't. There has been these creatures called, "Mimics" on the news. They are creatures that transform to look like people to trick humans and kill them, but sometimes there are clues that give it away, a physical mistake or do say something off. During your shift, you see the milkman. He gives you his I.D., everything is wrong. As he then presses himself up against the glass

"...Come on... Let me in..."