What are th four mysteries?

Please provide more context! "The four mysteries" could refer to many things. For example:

* Religious Mysteries: Are you referring to specific religious mysteries, like the mystery of the Trinity in Christianity, or the mystery of the divine in Hinduism?

* Literary Mysteries: Are you talking about a specific set of four mysteries in a book series or a genre of literature?

* Historical Mysteries: Perhaps you're thinking about four unsolved historical events or unsolved crimes?

To help me understand which "four mysteries" you are asking about, please provide more information.