I looked for books by this author after reading her bestselling book "Gone Girl", which was also made into a movie that was also pretty good.
I didn't like this book quite as well. In fact, I started on it once, and put it aside, because it was a little too creepy to read at bedtime, which is when I usually read.
Then I picked it up again, to read on the back porch, and got hooked and finished it.
It's fiction. The story of a young woman, Libby Day, whose family was murdered when she was a child and her brother was, possibly wrongly, convicted of the murders and sent to prison.
Now, members of a "murder mystery club" want to talk to her and get her help in re-investigating the murders to find the "real" killer.
So the story alternates between past and present, as Libby Day reveals her memories of the night of the murders, and contacts family members and friends to see if they can offer up any new clues.
Good writing, but many times the story seems far fetched.
A movie was made from this book, as well. The reviews were not so good on this one.