The Body in the Library is the second Miss Marple mystery that Agatha Christie wrote. It was published in 1940, a full twelve years after the first Miss Marple mystery.
I read this book because, as a youth, I loved Hercule Poirot, but disdained Miss Marple. I don't know that I've ever read all of the Poirot mysteries, but I knew I had not read more than one Miss Marple mystery. I decided to rectify that, and this was the handiest title available at the library when I made that decision.
Close friends of Miss Marple's awake one morning to the discovery of the dead body of a young woman in their library. Police suspicions naturally fall on the man of the house to begin with, and the lady of the house calls on Miss Marple to help solve the crime and confirm her husband's innocence.
I enjoyed Miss Marple more than I would have expected when I was a young lady. Agatha Christie writes enjoyable mysteries. Presumably you are already familiar with her work, so, if you like Christie's books, you'll probably like The Body in the Library. If you don't like her books, you won't like this one either.