The mysterious stranger left the room as soon as we arrived.

Foo fighter was the mysterious word used to describe the pilot in World War 2. This was used to describe various UFOs and mysterious objects flying over Europe during that time.

Well, you want to be upfront about your feelings, but then you want to be a little mysterious. Don't be too upfront or in their face, but don't act so mystrious so they can't figure you out.

The series was called THE PRISONER.

more mysterious and most mysterious