A mystery person or thing is one whose identity or nature is not known.
The mystery hero immediately alerted police after spotting a bomb.
那个不知名的英雄发觉炸弹后马上报了警。
mysteries
A mystery is something that is not understood or known about.
The source of the gunshots still remains a mystery.
枪弹来自何处依然是一个迷。
If you talk about the mystery of someone or something, you are talking about how difficult they are to understand or know about, especially when this gives them a rather strange or magical quality.
She's a lady of mystery.
她是一个神秘的女人。
A mystery is a story in which strange things happen that are not explained until the end.
His fourth novel is a murder mystery set in London.
他的第4本小说讲述了一起发生在伦敦的神秘谋杀案。