mysterious in a sentence

Definition

MYSTERIOUS: having an enigmatic or puzzling quality that evokes curiosity or intrigue.

The fog created a mysterious ambiance around the ancient castle.
She received a mysterious letter that had no return address.
The disappearance of the scientist remains one of the most mysterious cases in history.
His eyes held a mysterious depth that intrigued everyone who met him.
The old book contained mysterious symbols that no one could decipher.