Other forms: mystiques
An air of mystery around someone gives that person a certain mystique, like your glamorous next door neighbor who's rumored to work for the CIA.
The noun mystique is good for describing someone you find fascinating, like your beautiful and mysterious French teacher with that special mystique. A place or an object can also be described this way; many travelers are attracted to India's mystique, for example. The root of mystique is thought to be the Greek word mystikos, "secret or mystic."