Okay.

I read a book of literary theory in about 2003, but I believe it was older than that.

The book was about the connection between mystery / detective novels and ancient religious mysteries. As I recall, it had individual chapters on the Eleusinian mysteries, the Cybele and Attis myth, and other mythologies — focused on ancient religions prioritized by Western perspectives.

The book is not The Sleuth and the Goddess: Hestia, Artemis, Athena, and Aphrodite in Women’s Detective Fiction, but it would be that kind of thing.

I think it also contained some more common ideas about mysteries, such as that they exist to resolve anxiety about societal instability.

Thank you!