It is about a noble who got unhappily married. He eventually kills her wife, which causes his mental state to slowly deteriorate. It is supposed to be a quality book (I chose it for finals at high school from literature). My interpretation may be different from the consensus; however, I think the main theme of the book is the author trying to explain his philosophical views.
I am a mainstream reader 🤷♂️. If you are used to the The Hunger Games i recommand you "The Ballad of Songbirds and Snakes". It is the prequal to the main story and deals with the young President Snow becoming evil. Its been very gripping.