A disguised nemesis
We had a close call in home security the other day. A very suspicious character came to the front door wearing a Santa hat. But I instantly noticed her telltale blue uniform and bag and deduced that she was my nemesis the mailwoman. (How did I leave her off my Enemies List??) Well, I let her know all about what I thought of her sneaky disguise. She won't try that again any time soon! Pretending to be Santa. Of all the low-down tricks.
I'm raising the Mail-person Threat Level to Red, indicating current and ongoing covert mail-person infiltration attempts.