Sentence for enigma?

(Specifically, an enigma is a type of riddle generally expressed in metaphorical or allegorical language that requires ingenuity and careful thinking for its solution. But it is used generically to...

How he escaped his room with the door locked from the outside is indeed an enigma.

It is a noun. Example: The enigma of her identity continued to distract him for the rest of the day.

What role Bobby had in the store fire remains an enigma to this day.

Enigma: An seemingly unbreakable code that originated in WWII when the German's used it for communication. It now means just that - a difficult code to decipher or a mystery. "His body language...